I routinely brew IPA's and IIPA's with between 12 ad 16 oz of hops to 6 gallons. I mostly do a large dry hop at 5 days but sometimes do a 7 and 3 day dry hop, splitting the amounts in half and the aroma is killer. Sadly, it doesn't last very long so drink up.
+1. I use a lb in an AIPA pretty regularly.
OP - For reference, 2 -2.5 oz dry hops (5 gallons) is fairly common for APA-level hop character. I use 5 -6+ oz dry hops for AIPA, 7 days. 8- 12 oz dry hops for IIPA, half each in separate 5 day hopping additions.
As for hop stands/whirlpool/steeping, you have to decide what you want to accomplish. If you're looking to pick up some bitterness as well as some hop flavor and aroma, adding the hops from flameout down to 185F will accomplish that. I prefer to get basically all of my bitterness from the boil addition, so I like to cool to 170F before adding the hops. You get very little to no noticeable bitterness at this temp, and additionally less of the volatile oils are driven off as compared to adding at flameout, leaving better flavor and aroma IMO. Good luck !