Hey this is Loran Kelley, I own Polymer80.
The new material of the Phoenix 2 does make for tight rear takedown holes, if you take a 1/4 drll bit and reem the LEFT side towards the forward position it will solve that problem, we are aware and fixing this issue on future units on our end.
Regarding the safety selector position this not normal and infact the first I have heard of it. I could not see the images you posted here. Can you please send them to: email@example.com and I will assess them. if this infact a defect, we have a lifetime warranty and we will honor it. The buffer detent issue is news to me as well. You may have gotten a bad unit, and again if the issues with that particular unit are interfering with satisfactory functionality and performance, this is not acceptable to us either and we will replace the unit at no charge.
Please let me know. Thanks!
CEO, Polymer80, inc.