Part 1:
Yes

Part 2:
Photoshop, with assorted Topaz, Nik and ON1 plugins. I have no use for Lightroom.

Subscribe. Only use Photoshop, have not use for Lightroom.

Tamron 16-300mm f/3.5-6.3 on Nikon D5500.

I just today (finally) upgraded to PS v 21.0.1. I feared the worst, after reading this thread. However, what I have tried has worked fine. White balance changes in Camera Raw happened immediately. The crop tool worked fine (though the edges looked a bit different). My computer is at least 10 years old, a Dell Precision M6400 laptop. I suspect its specs are nothing special: (1) running Win 7 Pro (about to be a problem) Service Pack 1, (2) Intel Core 2 Duo CPU T9600 @2.8 GHz, (3) 8-GB RAM and (4) 64-bit operating system. I realize that this doesn't help those who have had problems, but I thought I would report that (so far) I have no problems.