The touchscreen on my enV Touch can be extremely inaccurate at random times. I have to open and close the phone numerous times to get it working right. Even after collaborating the screen it still happens, which is very irritating. My enV also gets very hot while charging..
All of these problems along with the bugs with texting on the touchscreen is putting me on the verge of returning this phone for a different handset.
The battery heating issue has been mentioned before. I believe Verizon will replace your battery to take care of it. Your touchscreen problem sounds like you may just have a bad one. If you like the phone otherwise, I would certainly take it back for a replacement.
I definatly think you have a defective phone. I think the touch screen is great on this. I had the Samsung Glyde before this, which was a horrible experience. The screens are plastic, so make sure you buy the screen covers. They will get scratched and work like crap. the glyde almost steered me away from touch screens all together. But i love my LG touch. Battery life sucks.. but im going to get a extended battery for 50 bucks and should help out.