Normal use is no issue. For pics zooming, just space your fingers apart a little then move outwards. For any games that just require 1 finger to tap all no issue. Issues start when u play games that need 2 fingers that keep moving around. Best eg are those emulator games or action/adventure games that have virtual keypad on left then buttons on right. When I just started to use 535 back in March, it was horrible to the point it can't register that I was pressing anything on the right when moving the virtual keypad on the left. After 3 updates, at least now I can play emulator & action games so issue is not that bad now. But unfortunately none of the updates can fix the touch screen issues when charging phone, my advise, don't use the phone when charging. This phone is missing the EMI shielding so I don't think this can be fixed with any software update.

What heating problem? Haven't encountered it at all. I actually play games on this phone haha 

Front camera quality is good enough, it's better than all my other Lumia front camera that's for sure. In fact, anytime I help someone take selfie, I pull the 535 out instead of my main 1520. 

Oh my, does it even show the Nokia logo when trying to start or nothing at all? Or it works without a SIM card?