Changelog notes:

Version 2.1 makes it easier to parry attacks, since 2.0 made it pretty hard compared with vanilla. Should work fine now.

For Version 2.0 I'm changing the way AHK remaps the keys, this allows me to address that horrible bug where the movement keys get stuck as if they're being constantly pushed down. This bug has been inherent to AutoHotkey since it was created and there's nothing I can do about their code. 2.0 does however eliminate most occurrences and make it so a subsequent press of the stuck key will free it. PLEASE do tell me about any effects you're experiencing.

DESCRIPTION

It's no secret to anyone what a screw up the key mapping in this game is. I'm sure half of us players use Loshirai14's excellent Better KB Layout, while the other half use Autohotkey. While Loshira's file works just fine, it doesn't really allow remapping for each user, at least not for your average non programing savvy player.

Autohotkey allows infinite remapping options, but learning to use it and opening/closing the app every darn time is kind of a hassle. Especially if you like having your game shortcut on the desktop or the start menu.

The best of both worlds is what I'm posting here. You DO need to install Autohotkey, but that's where the hassle ends. A simple batch file and a remap file is what you're getting. Much like Loshira's file, These open and run Both Autohotkey and DOA itself together, and closes them both when you exit to desktop from in-game. This effectively cleans the remapping so your keyboard goes back to normal the second you stop playing.

INSTRUCTIONS

You merely need to:

1. Download and Install AutoHotkey from HERE
2. Identify which executable you use to play the game (the vanilla game.exe, or the mod friendly gameSR.exe)
3. Download and extract the proper file and put the contents in the game folder (where game.exe is)
4. Double click "gameSR_VK_Remapped.bat" or "game_VK_Remapped.bat" to play.

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By using this mod as it is, the M, J, K, L keys automatically change to the Arrow Keys. So:

To KICK you use RIGHT ARROW (Remember this also Cancels options in the menu, like L does) 
To PUNCH you use UP ARROW
To GRAB/THROW you use DOWN ARROW (Remember this also Confirms options in the menu, like M does)
To GUARD/PARRY you use LEFT ARROW

And for the sake of convenience:

TAB opens the menu, like ENTER normally does.
RIGHT CONTROL scrolls option pages left like the key I does.
NumPad0 scrolls option pages right like the key U does.
Right Shift Taunts the opponent, like the key N does.

NumPad8 zooms IN during theater and navigates options up instead of the UP arrow key
NumPad5 zooms OUT during theater and navigates options down instead of the DOWN arrow key
NumPad4 pauses scenes during theater and navigates options left instead of the LEFT arrow key
NumPad6 resumes paused scenes during theater and navigates options right instead of the RIGHT arrow key
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By using the Optional file WASD, the M, J, K, L keys automatically change to the W, A, S, D Keys and the arrow keys allow you to move. So:

To KICK you use the D key (Remember this also Cancels options in the menu, like L does)
To PUNCH you use the W key
To GRAB/THROW you use the S key (Remember this also Confirms options in the menu, like M does)
To GUARD/PARRY you use the A key

And for the sake of convenience:

TAB opens the menu, like ENTER normally does.
The Q key scrolls option pages left like the key I does.
The E key scrolls option pages right like the key U does.
The F Key Taunts the opponent, like the key N does. Effectively turning it into the "F*ck you Key"

NumPad8 zooms IN during theater and navigates options up instead of the UP arrow key
NumPad5 zooms OUT during theater and navigates options down instead of the DOWN arrow key
NumPad4 pauses scenes during theater and navigates options left instead of the LEFT arrow key
NumPad6 resumes paused scenes during theater and navigates options right instead of the RIGHT arrow key
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By using the Optional file NumPad, the M, J, K, L keys automatically change to the 8, 4, 5, 6 Keys on your number pad and the arrow keys allow you to move. So:

To KICK you use the 6 key (Remember this also Cancels options in the menu, like L does)
To PUNCH you use the 8 key
To GRAB/THROW you use the 5 key (Remember this also Confirms options in the menu, like M does)
To GUARD/PARRY you use the 4 key

And for the sake of convenience:

TAB opens the menu, like ENTER normally does.
The 7 key scrolls option pages left like the key I does.
The 9 key scrolls option pages right like the key U does.
+ key (on the numpad) Taunts the opponent, like the key N does.
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USING YOUR OWN KEY LAYOUT

"Ugh. But these are like... your opinion man!"

I know... The point of making this mod when a rather good layout mod already exists is to be able to REMAP everything to YOUR taste. If you wanna get in the rabbit hole, read on; otherwise, my lazy friend, remember that there's an alternate DOA5.ahk as an optional file, with which you can use the arrow keys to move, and the WASD keys as face buttons, if that sounds more sensate.

So if you DO want those keys exactly your way, that's where the notepad enters. You're copying 2 files to your game directory. The .bat file you use to run the game, and the DOA5.ahk file which contains the new layout.

To use your own key layout simply Right click on DOA5.ahk and select Edit Script from the menu, it should open the notepad showing you something similar to this:

Note: This template has changed as of v2.0. I know it looks like a wall of nope, but I'm working on an exe to wrap this up and do the heavy lifting on a simple press to remap basis. For now this WILL work if you give it a shot.  
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#NoEnv
; #Warn  ; Enable warnings.
SetKeyDelay, 10
SetWorkingDir %A_ScriptDir%
#HotkeyModifierTimeout 1

;-----------------------------------

;This one is for PUNCH
$Up::Send, {k down}
$Up up::Send, {k up}

;This one is for PARRY
$Left::Send, {j down}
$Left up::Send, {j up}

;This one is for KICK and Cancel
$Right::Send, {l down}
$Right up::Send, {l up}

;This one is for THROW and Confirm
$Down::Send, {m down}
$Down up::Send, {m up}
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Just Ignore the first paragraph before the dash line and focus on the list of key changes afterwards. what you need to do is as simple as replacing the first key on each line after $ with the key you wanna use. Do NOT touch the key between {}.

So for example, if you wish to use Space to confirm selections/Throw the opponent, just as if it was the M key, you simply find:
-------------------------------
;This one is for THROW and Confirm
$Down::Send, {m down}
$Down up::Send, {m up}

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And replace Down with Space, like so:
-------------------------------
;This one is for THROW and Confirm
$Space::Send, {m down}
$Space up::Send, {m up}

-------------------------------

Do the same with any keys you need to change and save the file. A list of proper, accepted key names is found HERE. Things to note:

- If you don't like any of the remaps, simply delete the 3 lines containing it. Like say, you don't want Tab behaving like Enter, simply find:

--------------------------------
;This one is to open the game menu
$Tab::Send, {Enter down}
$Tab up::Send, {Enter up}

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And erase the whole 3 lines, OR type a semicolon BEFORE the 2nd and third lines to comment them.

- Last thing to note is that when you remap a key, the original key will STILL retain its function, unless you remap that key as well. So using the default layout I provided, the M, J, K, L keys will work normally in addition to the new remaps, since I didn't use lines that command those keys to do anything different.

When you're happy save the changes, close Notepad and open the game with the .BAT.

USING A SINGLE KEY FOR A FULL COMMAND

As requested by user Genie44, a way to remap a single key to let's say, execute an entire combo, is to add the following lines to the file, so as usual right click on DOA5.ahk and select Edit Script from the menu and add to the very bottom of the script:

;This one is a Right Forward half U + PUNCH
$x::Send, {s down}{Sleep 50}{s up}{Sleep 100}{d down}{Sleep 50}{d up}{Sleep 100}{k down}{Sleep 50}{k up}

That line will make it so pressing the X key executes Down > Right > Punch, just note that this will only work while facing right. You'd need a second remap line to do the same while facing left. So to use the Z key to Down > Left > Punch you also need:

;This one is a Left Forward half U + PUNCH
$z::Send, {s down}{Sleep 50}{s up}{Sleep 100}{a down}{Sleep 50}{a up}{Sleep 100}{k down}{Sleep 50}{k up}

This opens into ANY combo you can possibly want, even those 15 hit combos that drain 75% of the enemy's health but only Stephen Hawking would be able to memorize.

So for any combo you wanna add, you need a new line of code, placed as always in a separate line at the end. The important thing to remember is that each key hit in your combo needs this template:

{s down}{Sleep 50}{s up}{Sleep 100}

This guarantees there's a sensible timing to the key stroking, and the keys won't get stuck. It basically means the S key (down/crouch) will be hit and held for 50 milliseconds, then be let go of, and then wait 100 milliseconds until the next key stroke.
All you have to do is copy - paste the template for each key stroke in a combo and replace the s with whatever original key you need to be pressed. Make sure ALL key strokes are in the same line, one after the other, like in the example.

Too complicated? Feel free to request a custom line for any combo with any character you want and I'll hook you up when I have the time.

CONCLUSION

I know this isn't exactly the hottest game of the month, but I still play it and the Beach Paradise mod gives it new breath every day. I wish I had these files when I started playing, so I hope at least someone will appreciate them. I'm around in case anyone has any questions.