There is a lot off issue with aftermarket parts. Everything may look good but as you have mentioned there is a sharp edge. Not much can be done except for trying to sand the edge down more. I say if you can live with or maybe put a case on it would be the best solution.
2 issues that i can see here. (1) Poor connection did not set the cable back correctly - easy fix reset the cable and be extra careful (2) Damage the display connection --No fix available without changing main board (best is to buy a new one)
The only External LDI indicator for the Iphone 6/6P is in the SIM card slot. It is hard to see on the darker models. It is located on the case tucked behind the inner edge of where the SIM trey slides in.