How about dry hopping? I'm thinking of doing my 3 gallon batch in my 7.5 bucket, but I also want to dry hop. Would it still be ok to crack the lid to drop in my hops quick and seal back up?
Yeah, I do it all the time. Just be careful not to drop something in there other than hops.
3 gallons in a 7 gallon bucket may be too much head space though. Why aren't you putting 5+ gallons in there?