LCD Backlight and Silent switch/sleep and wake button

I recently had my iPhone 5s screen replaced by a local iPhone/Mac repair shop. I had water damage and the digitizer was unresponsive along with water behind screen. They replaced it and it worked great. Another issue was that my silent/ring switch doesn't work nor does the wake/power button. They told me they could replace for another $40. I'm low on cash and asked them if alcohol solution could fix a tripped moisture sensor. He said it might work but no promises. A week later, my iPhone screen started to have shadows and leave the image of the app on the screen, even after it was closed. It was like plasma screen burn in. They replaced it with a new screen and it was covered under warranty. This new screen works great but has another odd flaw. I can see the light coming from below, similar to how a Gameboy Advance SP shined light on the screen from below. Colors are great and responsiveness is great too. Is this a major issue or am I just a little paranoid? Help would be appreciated along with the sleep/wake issue. Also, after they replaced my screen for the second time, my home button sticks, which it never did that before. The store told me that was due to moisture damage, but it never happened the first time or when I first brought it in.