Most keyboards no longer use springs but instead use rubber. the only exception to this is mechanical keyboards and those can be identified by clicking when you press a key. the best bet would ether use a donor keyboard or replace the whole keyboard
what i would try first would be to defragment the files on the drive using a defragmenting program window has one built in to see if that would fix the issue if it does not then the issue is probably the drive itself. hear is a good video of what it does and how it works https://www.youtube.com/watch?v=XSvOfu2P...
From what you are describing it is normally for batteries to slowly loose its charge capacity over time. on the other hand it should not loose it that quickly. it is possibly you have a bad battery but i would try this to see what happens over the coarse of a few days try and let the battery die then charge it fully and repeat if that does not do anything then i would look and see if the replacement battery came with a warranty and go that route.
for things like this specs do not matter what matters is the layout of the board. short answer is probably going to be a no. long answer you would need to look at the boards physical size from every direction including the height of the components, the look at how the components are arranged. you will then have to make sure that your carrier will support the new guts of the device as well.
Most computers will give you a key to press to go into the bios as well as a key to go into the boot device menu. this option give you the various device that the computer will boot from. according to http://tim.id.au/laptops/acer/travelmate... on page 35 this key is f12.
I would see if you can see anything on the screen when you get it into the light just right you will need to use a bright source of light if you can then it is a back light issue. if you can not then the problem is ether the screen or the the device itself.
With out looking at it may and may not be fixable. On the other hand things like this are not really fixable. if it is fixable you would need someone that know what there are doing with a soldering iron. sorry i know that is not the answer you are looking for for.