Places of power
Changes related to the places of power were done in "blob0.bundle\gameplay\abilities\effects.xml". Look for <ability name="ShrineEffect"> and <ability name="ShrineAardEffect">.
Also find this line in scripts, and revert all changes related to it:
theGame.GetDefinitionsManager().GetAbilityAttributeValue('ShrineEffect', 'duration', durationMin, durationMax);
Swallow potion healing strength and duration
May be changed in these files:
"blob0.bundle\gameplay\abilities\effects_potions.xml" → "SwallowEffect_Level1", ..., "SwallowEffect_Level3".
"blob0.bundle\gameplay\items\def_item_alchemy_potion.xml" → "Swallow_1", ..., "Swallow_3".

Modifying item stats using Potato Item Cheats
Select armor in inventory, then try these console (~) commands:
PIC_ShowAbilities(1) // This is a comment. Do not copy this part. This command will display "stats names" in tooltip, replace 1 with 0 to turn off.
PIC_AddCraftedAbl('NL_SlashingResistance_5', 1) // Adds +5% resistance to slashing damage and +2.5 armor. Second argument specifies number of abilities to add. Meaning, if you pass 2, +10% resistance and +5 armor will be added.
PIC_RmvCraftedAbl('NL_SlashingResistance_5', 1) // Removes previously added ability

PIC_AddCraftedAbl('NL_SlashingResistance_1', 1) // adds +1% resistance to slashing damage and +0.5 armor.
PIC_AddCraftedAbl('NL_PiercingResistance_1', 1)
PIC_AddCraftedAbl('NL_BludgeoningResistance_1', 1)
PIC_AddCraftedAbl('NL_RendingResistance_1', 1)
PIC_AddCraftedAbl('NL_ElementalResistance_1', 1)
PIC_AddCraftedAbl('MA_Armor', 1) // +1% to all 5 resistances, and +2.5 armor.
Stat names 'NL_SlashingResistance_1', 'NL_PiercingResistance_1' are from "modNoLevels_v1_5_0\extras\Potato Item Cheats\abilities\def_item_quality.xml". There you can see all available abilities and their stats.

Here are some commands with other ability names, which you may be interested in:
PIC_AddCraftedAbl('PIC_Armor_m100', 1) // minus 100 armor points
PIC_AddCraftedAbl('PIC_Armor_m10', 1) // -10
PIC_AddCraftedAbl('PIC_Armor_m1', 1) // -1
PIC_AddCraftedAbl('PIC_Armor_1', 1) // +1
PIC_AddCraftedAbl('PIC_Armor_10', 1) // +10
PIC_AddCraftedAbl('PIC_Armor_100', 1) // +100 armor points
PIC_AddCraftedAbl('PIC_SlashingResistance_m5', 1) // -5% resistance to slashing damage
PIC_AddCraftedAbl('PIC_SlashingResistance_m1', 1) // -1%
There is no '...m2, '...m3', '...m4' in between. But you can add -5 few times, and then -1 few times.
PIC_AddCraftedAbl('PIC_SlashingResistance_1', 1) // +1%
PIC_AddCraftedAbl('PIC_SlashingResistance_5', 1) // +5%
PIC_AddCraftedAbl('NL_PiercingResistance_m5', 1) // -5% resistance to piercing damage and -2.5 armor.
PIC_AddCraftedAbl('NL_PiercingResistance_m1', 1) // -1% and -0.5
PIC_AddCraftedAbl('NL_PiercingResistance_1', 1) // +1% and +0.5
PIC_AddCraftedAbl('NL_PiercingResistance_5', 1) // +5% and +2.5