Professional brewers pump in CO2 when dry hopping to agitate settled hops. Here's a recent reddit thread from /r/TheBrewery with some discussion around it.
Sounds fine. Hot-side aeration might be a concern. John Palmer mentions it in How to Brew, but Brulosphy did 2 exBEERiments (part 1, part 2) on it and neither led to significant results.
Whirlpool hops should be added around 170ºF and leave them for 20-30 minutes. Your wort should be alright...
This thread is a bit dead, but I'm bumping it because I plan on trying to brew a kettle sour with my sourdough starter this weekend. My starter was spontaneously cultured in my apartment and has made some pretty solid bread, but I've kept it pretty thin so nothing has been too funky. I'm going...
FWIW, I brew with one of these baskets (from Brausupply) and the only downside is how annoying it is to clean. Besides that I would say it's worth picking up and trying.