Thank you so much for the reply!
Is there any way to tell if the fiberglass of the hull has been damaged? Is there structural wood sandwiched in the fiberglass that could have been damaged/rotted without being visible?
The C22 is an excellent learning platform. Thousands have learned to sail on a C22, myself included.
The C22 hull isn't cored, which is a good thing. I think the keel is attached by bolting it through plywood (because that's the way the C25 and C27 keel is attached). If water gets to the plywood, it gets soft and rots, requiring a fairly major rebuild of the keel stub. One way in which it can get wet is if water collects in the bilge and freezes during the winter, cracking the seal. I don't know how you could determine whether the keel stub is damaged other than to drill into it and see if wet mush comes out, but I wouldn't recommend doing that. If the plywood is really soft and mushy, you might
be able to determine that by lifting the boat in a travelift and shoving the keel back and forth very hard to see if it flexes at the stub.
I don't know what you are referring to when you talk about the drain in the bottom of the boat. It could be an open hole for a knotmeter or depthsounder transducer, or it could be a hole where a thru-hull valve should be. In any case, it sounds like something is missing that needs to be replaced, and that is an expense that must be factored into the equation.
I'm not sure what it is that you describe as "...slight cracking (separation) of the fiberglass inside the cabin where the bulkhead supports connect to the hull." As I recall, the interior of the C22 is formed by a hull liner. I don't think a crack in the liner is likely to be structurally significant. Nevertheless, without seeing it, that's not much more than a guess.
If the hull is significantly deformed from sitting on a trailer too long, you should be able to see that by sighting along the hull.
Coast Guard required safety equipment can be found at the following hyperlink. Required Equipment for Recreational Boats - BoatSafe.com
Also, every boat should have an adequate anchor and chain and a motor, and an oar is occasionally useful if the motor fails.
I'd like to be able to tell you to go ahead with it, but, if the boat has had a lot of water in it for a period of years, and has gone through repeated freeze/thaw cycles, I don't know any way of telling what damage it might have incurred. It's a gamble. If it is badly damaged, you might do a lot of work and spend a lot of money before you find that out, and then you'll have a big disposal problem. If it isn't seriously damaged, you might have a real bargain. You roll the dice - you take your chances.