battery and external montior issues

battery and external monitor issues:

first off i wanna start by saying these are two different macbook pro's with 2 separate issues

1: 15 inch mid 2012 (retina) macbook pro '4 core i7 2.6ghz, 16gb ram, dual graphics, 1tbssd.'

(i still use this laptop everyday)

i am pretty sure this is a battery issue but if not i will list my issues here. 1 being that this laptop is sometimes very slow and sluggish and other days feels new and quick, has an upgraded 3gp/s ssd 1tb. the battery needs to be replaced as it has over 1000 cycles and unplugged will not last more than maybe 45 min to an hour if you are lucky. however i keep this laptop plugged in at a desk connected to a thunderbolt display, so i have put this off dramatically as it never leaves its spot. i am pretty sure the sluggishness is due to the battery but just want some confirmation considering when it feels quick is usually after i let it die and then plug it back in.

2: mid 2012 13 inch macbook pro, (unibody) dual core i5, 16gb ram, new hdd, new battery.

this laptop has a bad keyboard, i plan on replacing the entire top case but before i do i want to make sure it is worth it to do so. this one has a slew of issues concerning me that it may have a failing board.

1st issue:

kayboard is basically unresponsive except top keys which basically wigs the laptop out and selects random items whenever it wants to, or when real bad will open launchpad about 1000 times on its own.

2nd issue: when opening a tab or application each tab or menu in application opens up as a new window?

i originally thought this was a software issue, but after multiple iteration's of mac os installations and 2 different new 2.5 inch hdd's have learned this is not the case.

issue 3: (in my opinion the worst issue)

macbook will crash/freeze when connected to any monitor INCLUDING apple thunderbolt or cinema displays. if connected before booting it will never boot or flash the apple logo just stay on a white screen for the entirety that the monitor is connected. this one is an issue bc i am attempting to dock the macbook and use it as a desktop with a keyboard and mouse to see what is and is not effected by the keyboard by unplugging it and booting it off the magsafe connector. or see if it can be used in general.

before i am plauged with "go buy another macbook". or "just upgrade already" i have a newer one that works just fine however i love old technology and it is a hobby of mine to keep them working smoothly and to give them purposes to be used for. on top of that the unibody mid 2012 was free so