Default ? about cases w/ built-in screen protectors & any silicone/plastic/silicone cases?

2 questions, first I am wondering about the cases with built in screen protectors like the kraken, harcore, etc (I know they arent out for the ET4G). when putting on a regular screen protector, if you have an air bubble under it, it looks like complete crap! I tried watching some videos and cant see any that look bad, but do the screen protectors in these cases not cling to the screen at all and is that why they look good without having to spend alot of time trying to apply the case while not letting air get trapped under the screen?

and 2, I have seen plenty of cases that have a silicone inner liner inside of a hard shell, then there is the cases that your phone sits in the hard inner plastic and then its surrouned by silicone. I like how the kraken covers all the ports with its outer silicone sleeve, but I would rather have my phone in silicone on the inside as well, because it seems to me there would be less chance of wear spots on the corners of the phone that my old phone got from being in a hard case for a long time.