Here's some notes I found regarding PA:
1.) Power Armor can be used by other NPC's while it has a power core. To prevent NPC use, remove the fusion core from your suit when leaving.
2.) When power armor is destroyed, you do not get the frame back. Take care of your frame!
3.) If you lose your frame, there are more out there. Crashed vertibird and military installations normally have spare frames or even full fledged suits available.
*Can also buy a frame from Diamond City armor vendor if needed
4.) Power armor, unlike regular attire, will degrade over time. To repair the pieces, you must have them either in your inventory, or on the frame, NOT stored in the workshop inventory. When they are in the appropriate place, going to the power armor rack and hitting craft will offer repair of pieces through the use of the triangle button.
5.) Power armor will not hang on the rack, but can be "stuck" to a rack by dismounting near the rack, entering the crafting menu via the power armor stand, and exiting.
6.) To exit power armor, hold the X button
7.) Power armour does NOT need a fusion core to be used.
Without a fusion core, power armor
-retains its weight carry increase
-resists the same amount of damage as powered armor
- Head mounted lights and mods will still work
-Weapons, including large weapons like mini-guns, can still be used
Features lost when not powered:
-unable to use VATS
-unable to sprint
-Movement speed will be reduced to overburdened walk speed
-Melee attack removed
It is still extremely beneficial to use power armor in areas with high enemy density, even if it is not powered!
8.) Buffout removes the movement penalty of unpowered power armor. (Most like the same for other varients of chem as well, untested)
9.) Power armor can be painted, and each paint scheme applies a bonus effect to power armor. You must have the full chest legs, hands, and head painted the same design for the effect to work.
10.) In addition to paint, mods can be made to power armor through the power armor crafting station, allowing multiple different varients of each design.
11.) Holding the O button while in power armor will turn on your helmets lamp light
12.) You can fast travel while in a power armor suit, both unpowered and powered, no need to walk all the way and waste fusion cores.