Some boats had the bilge sump pump at the forward end of the cockpit, where water pools when the boat is sitting level in the water. This may be one of these boats. If so, you want to check that the aft main cabin bulkhead is sealed above this pump. If not done--then something for you do do. Many boats with the bilge pump in the rear, just forward of the transom drain, also had the "drain" out of the cabin, where it is located in this boat. This was commented on at the first of this thread.
The boat looks very clean in the photo you posted.
I don't know of anyone who has put a jack plate on the 22's. I have run both the 22's and 25's in less than 18" of water, by tilting the motor up--it works very well, since you don't really want to go fast in these conditions.
Yes, both the 22's, 25's and 255 TC have wash down--both fresh and raw water. When you put a thru hull in the bottom of the boat, be sure and epoxy the rim of of the cut out. You do this both to seal the hull core, and to give a ring to compress the nut on the thru hull. Also some boats have a bait will, with pick up. Some pickups for both bait tank and wash down have been over the transom types to avoid thru hulls.
On this site (and mentioned in this thread) there are many threads about these engines having carburetors which have to be drained if not used regularly. (we drained if not used within a month). Rebuild of the carbs should be on that check list. The "old fuel" should be drained and new fuel put in the tanks (both). You need to have them drain the oil in your presence. It only takes a few minutes to drain and replace. That way you are sure what is going on.
I would have been concerned that the boat was not ready for sea trials, especially if there was a long drive involved. Be sure that your check list is taken care of before you return. One of the reasons I tend to be Leary of dealers.