So I finished my first all grain batch. Brew day was horrible (stuck sparge that wouldn't get unstuck), but I eventually got it done. I got less wort into the boil kettle than I should have and it lead to less wort into the carboy.
I got around 4.75 gallons in the carboy (I'm thinking I will lose a bit to settling, etc) so I'm thinking I will get about 4.5 gallons. I've never kegged before, and I got a nice sanke keg that I took apart and cleaned for kegging (I have all sanke couplers in my kegerator for local craft brew) but I'm wondering if it's a bad idea to keg less than 5 gallons. Is this okay or should I just bottle these and save kegging for the next batch? Also, is it okay to just dry hop in the keg rather than transferring to a secondary and either dealing with the mess from the pellets in the secondary? If I do dry hop in the keg, it will be in a muslin hop bag.