You have to change your digitizer. Happens sometimes. Maybe you bought a cheap brand or something. Buying a decent screen will help for sure. Also check all the ribbons and cables to your screen to make sure they're all put in the whole way. Sometimes being a little out can cause issues.
You'll have to change your LCD or Backlight. One of the two was damaged when it got water damage on it. My brother had the same thing happen to his ipod touch. Check around on YouTube. Some people may have found a way to fix it. I think it has to be replaced though. Sorry I can't be of anymore help. Best regards!
Yeah hate to say it but you'll have to change the digitizer. I know you don't want to but sometimes it's cheaper to fix the one big problem than look at all the little things it could be. Sorry I can't be of any help, but best of luck though!
Can be the fan is going too. The bearings in fans sometimes go. Especially if you blow them out with an air compressor. Try looking on ebay for a new fan for your cpu. Don't use a cheap thermal paste either. A decent one will be about $10+. I recommend this or this. Both are excellent paste's and have always kept my temps down on my computers. If you replace the fan I'm sure you won't have any issues with noise. Just for your information too. All CPU's and GPU's get hot when gaming. Most Intel processors can run upto 105c and AMD's can run around the same too. Anything up to 85c isn't of any worry for me usually. Just make sure it's in a good spot that has good airflow too. That always helps. Best of luck!
Take the battery out, hold the power button down for 60 seconds, put the battery back in. Then hold down the power button and it should start up. DONT have it plugged in when your doing all this. Hopefully that works for you!
Yes it can. Also rooting your device and messing around with stuff can do that too. Changing it's resolution, etc. Lots can go wrong when you play with things. If you don't know what your deleting .... usually best to leave it alone.
Can be from a couple things. Could be the ribbon that holds it in is being put under pressure when you put your finger on it. Can be also your digitizer isn't working. Maybe you pushed it on too hard when you installed it. Start with the easiest thing to test and go from there. Best of luck!