Did you ever find a replacement screen for this? I am looking for one as well. I think my next step is going to be to take apart the monitor and get some part # info off the LCD panel. It's very likely that a product like this uses a generic LCD panel that is widely available, but wouldn't be found by searching for a replacement part for this specific product.
As long as you do indeed have the 13 Inch Unibody MacBook Pro Model A1278 (or non-retina, as you called it) then yes, you can install an SSD in place of the optical drive and you can also upgrade the RAM.
All 4S models use the same replacement screen. In other words, there is no such thing as a "CDMA iPhone 4S Screen" or a "GSM iPhone 4S Screen". To be completely clear, the iPhone 4 and 4S actually use the exact same replacement screen assembly. The only difference is in the plastic frame/bezel that the replacement screen is installed into. The GSM iPhone 4 uses one frame, the CDMA iPhone 4 a different one, and then all models of the iPhone 4S use yet another different frame. So the moral of the story is that it's not a compatibility question. Perhaps the connector for the LCD on either the replacement screen or the logic board was damaged during installation. Or, since you said the phone was "pretty messed up", perhaps the logic board was already damaged when you got the phone.
The keyboard connects to the logic board through the trackpad on these machines. So perhaps the problem is with the trackpad. I actually recently ran into this with a customer's machine...it was acting as if the shift key was stuck down, so I replaced the keyboard. That didn't solve the problem so I replaced the trackpad and that turned out to be the issue.
If you have the 2009 A1342 model, then no, it does not support 16 GB of RAM. On the other hand, if you have the 2010 A1342 model, then you're in luck because as long as you're running OS X Lion or later it will support 16 GB of RAM. The PC3-12800 RAM that you have should be backwards compatible in place of the PC3-8500 that the A1342 MacBook came with, but it will not run any faster than 1066 MHz.
Could be a number of things, but most likely you're dealing with a faulty part. From my experience as a repair tech, aftermarket iPhone batteries have a rather high defective rate. On a side not, I would not recommend using hydrogen peroxide as a cleaning agent for sensitive electronics like this. Using legitimate electronics contact cleaner is the best way to go, but most people don't have that laying around the house. Most people do have 70% isopropyl though, and that will do just find in most cases.
I don't mean to sound rude, but I'll just be honest when I say that you're barking up the wrong tree here. There really is no way to upgrade an iPhone of any model. They're just not a device that was meant to be upgraded. The only option to upgrade an iPhone in any way would be to install a motherboard of the same model with more storage. In other words, you could replace your 16 GB iPhone 4 motherboard with a 32 GB version. Of course, that wouldn't help with performance, it would just give you more storage. If if upgrades were possible, they would be cost prohibitive. Heck, even just a straight replacement motherboard for your iPhone 4 right now would cost nearly as much as replacing the phone. You mention that you're looking to "speed it up". Have you done a restore of the phone and set it up as a new phone lately? Doing that periodically will keep the phone running at its best, as this gets rid of any clutter that has built up in the depths of the operating system that you can't see.
Be careful with these color conversion kits. Often the LCD will either be a reused Apple original or at the very least a very good copy, but unfortunately more often than not the glass is of a low quality. This means that it will be more susceptible to cracking. There simply isn't "OEM quality" glass in any other colors except for black and white in my experience. I know this doesn't really answer your question. Just a word of caution.
It depends on exactly what you mean by replacing the home button. Are you talking about replacing the actual plastic home button key? If so, yes it is very possible to do that. If you're talking about replacing the home button flex cable, then that's a different story. I haven't worked with the 5th gen iPod Touch a whole lot, but if I remember correctly, the home button flex is soldered onto the Lightning port assembly. This makes replacement very difficult at best, and impossible at worst.