I bought a Catalina 25 new, and raced and sailed it for over 20 years before I moved up to my present boat. I've never seen any other boat that was so capable of sailing so much better than it's rating.
The notion that Catalina quality is "not all that great" was nurtured for many years by competing salesmen at boat shows who were having difficulty selling similar but more expensive boats. Buyers found that they could afford bigger Catalinas with more accomodations than the more expensive brands, and most of them didn't need such sturdy boats just to cruise a big bay or the coast. Competing salesmen had to puff the quality of their boats vs. Catalinas in order to make sales. There are indeed better boats, but, if you're looking for a coastal cruiser/racer, Catalinas are a very good value. Don't be afraid of a Catalina, but some of the higher priced boats with better reputations can now be bought in the same price range as Catalinas, now that they are depreciated.
Your price range of 2.5 to 3K for a C25 is in the range for a decent older boat without a trailer. A boat with a trailer will cost about another 2k. You can spend 1k on boat maintenance in the blink of an eye, to replace just one sail, for example. So, if you find a boat for an extra 1k that has been better maintained, and has better, newer equipment, you may be way ahead of the game.
Daggerboards are a type of centerboard that are usually found in smaller dinghies. Offhand, I can't remember any in cruising boats, although there might be some. Generally, a fin keel sails well, but you need 4' of water and a trailer tongue extension to trailer-launch it. A wing keel doesn't point to windward quite as well as a fin keel, but it needs less water depth to launch it, and, if you run aground, it can be a little more difficult than a fin keel to break it free. Some older C 25s also had a swing keel. They sail as well as a fin keel, and provide shallow draft, but the keel-raising mechanism absolutely must be meticulously maintained.
I have to tell you that you really don't want to bump a stump too hard with the keel of any boat, no matter who built it. You should ordinarily stay out of shallow water, but whenever you have no choice, slow down and proceed with caution, so that you won't do any serious damage if you hit something.
Some monohull sailboats are ballasted, and some are not. With a few exceptions that aren't relevant here, ballasted monohulls are generally self-righting, but unballasted ones are not.
In moderate winds, it doesn't make much difference whether you hike out or not on a ballasted sailboat. In exceptionally strong winds, it can help to reduce the angle of heel if you have extra crew sitting on the windward rail. On the other hand, in exceptionally light winds, if you have enough crew members, you can put them on the lee rail and force the boat to heel. That usually reduces the boat's wetted surface (which reduces the amount of drag) and it also improves the sails' shape, which helps them continue to drive the boat, both of which help keep the boat going in light air.