Re: Help pinpointing a leak
"but they tell keel was alarmingly loose when it was in the lift. I'm wondering if instead of rebedding we would be okay grinding that smile out and filling with 5200. "
If the keel is indeed "loose" that is a serious structural issue and you'd want to find out what has failed, whether it is part of the hull structure, or the keel bolts, etc. and then make sure a proper structural repair is made if needed.
If the keel actually needs to be dropped and rebedded, using 5200 as the bedding compound can actually structurally adhere the keel to the hull. Not that you'd want to skip keel bolts--but a proper 5200 bond can make the keel bolts superfluous. Or redundant.
You may want to eyeball this yourself, and get a second professional opinion.