Ever thought it's weird that you can join up with (and even become the leader of) almost every faction in the game, and nobody bats an eyelid about it? Well, no more. Vvardenfell's factions are cracking down on fraudsters who are joining both the Tribunal Temple and the Imperial Cult for the services, the Mages Guild won't just let the Archmagister of House Telvanni waltz in and take over, and the three main warrior factions on Vvardenfell are now demanding a little more loyalty from their soldiers.

Major changes in v1.3:

• Assorted bug fixes and dialogue improvements
• Added optional "Morag Tong Freedom" version that allows you to join a Great House and the MT.
  
  

Major changes in v1.2:

• Overall, this update aims for less 'restrictive' and more 'reactive' - NPCs will respond to the choices you make, but fewer faction combinations are cut off entirely.
• You can now ask Baladas to write you a letter to the Mouths in Sadrith Mora, recommending that you be allowed to join the House. This provides a way to join House Telvanni if you joined the Mages Guild first, but is also open to non-MG members. You'll have to do him a favour first, of course.
• Can now join one of the Great Houses as a member of the Morag Tong. However, in breaking your vow to the Morag Tong, you just pissed off a lot of assassins. Your former friends might not be so friendly now. You still can't join the MT as a member of one of the Great Houses.
• You can now join the Temple as a member of the MT (and the MT will tolerate it). I made this decision because contracts on Temple priests are probably quite rare (falling outside the House War contracts), and could reasonably be passed to another assassin.
• You can now join the Legion and House Redoran as a member of the Fighters Guild, and vice versa, you just have to convince them you're worth the potential hassle (disposition > 70).
• Neminda will now warn members of the Imperial Cult about House Redoran's Tribunal Temple affiliations, in case that changes your mind.
  

PAQ
Pre-emptively asked questions

But won't this mean that I can join far fewer factions?
Well, yes! Making many of the factions mutually exclusive forces you to choose more carefully where your allegiances lie, and adds more roleplay flavour to a playthrough. Are you a common sellsword, a loyal citizen doing your duty to the Empire, or an honorable warrior seeking to prove yourself and gain glory for your House? Do you believe in the Three, or in the Nine? Will your partake in political life as a member of one of the native Dunmer factions, or help regulate it as an assassin for the Morag Tong?

But - quests! Will there be enough to do?
There will still be loads of quests available to you, and if you find you need more to do - this is a perfect opportunity to try out some quest and dungeon mods.

Features

• Flavorful dialogue for faction refusals
• Tribunal Temple and Imperial Cult are now mutually exclusive
• The Temple Masters now have special commentary for members of House Redoran and House Telvanni seeking to join the Temple
• House Telvanni and the Temple aren't mutually exclusive, but you'll need a very high disposition to persuade one to allow you to join if you've already joined the other. The Telvanni are a bit more suspicious of your motives than the Temple (90 disposition vs 70).
• Mages Guild and House Telvanni are now mutually exclusive ... mostly.
• There is a way to join House Telvanni as a member of the Mages Guild
• As of v1.2 there is also a way for members of the Mages Guild to join House Telvanni.
• Mages Guild and Temple are mutually exclusive at mid-high ranks (Magician/Curate). 
• Fighters Guild is no longer mutually exclusive with Imperial Legion and House Redoran; you can join up, but you have to impressive (disp 70)
• Neminda will warn members of the Imperial Cult that House Redoran prizes its relationship with the Tribunal Temple.
• Membership in the Imperial Legion and the Great Houses is mutually exclusive
• Membership in the Morag Tong doesn't prohibit you from joining other Dunmer factions - but they'll be VERY unhappy if you join a Great House after swearing an oath to the Morag Tong.
• Membership in a Great House prohibits you from joining the Morag Tong
• The Thieves Guild and the East Empire Company will still accept all suitable candidates. They don't care what you do in your spare time as long as the gold flows ;) 
  

This should be compatible with most things. Please let me know if you encounter any issues.

Credits

AliceL93 - Ideas and design
Lucevar - Dialogue and implementation