We have a pair of inc 2 phones and I have 0 issues with either. That ridge you speak of helps to protect the screen when you lay the phone face side down, plus it helps prevent accidentally touching the screen when you handle the phone and inadvertently opening an app.
As for cases, I have tried several and we prefer the cheap TPU S- line cases from China that cost about $3-$4 each. They are tough, fit perfectly, easy to hold, and not sticky like silicone cases. I have bought assortment of colors, they take a week to 10 days to arrive from China. Search eBay.... incredible 2 TPU s line case.
Only thing about these are they fit very snug and takes a little effort to pop them onto the phone. My son in law has an otter box and he doesn't care for it and neither did I. You can buy a dozen or more of these for less than one otter box.