S2 is known for better than average gelcoat and fiberglass work. The 9.2A's rating is average at about 180. Mine sails well and loves the wind. She heels initally, but I have had her 20 degrees over with the rail in the water in 20+ knots and she is quite predictable. The aft traveler has pluses and minuses. In windy SF it will be a plus to have the main sheet handy, a familiar control in a smaller boat but one not quite as used in larger boats which tend to just change heading to spill wind. However, the main sheet is long and can be a pain to keep under control sometimes, as it turns into a task to keep it controlled and not lying all over the place when sheeted in.
Blocks go on the toe rail. Admittedly that means that most people probably just mark one or two locations on the toe rail for conditions or differnent sails and move them infrequently. However, I bet most people do not adjust their genoa cars that much either. The track does give you more flexibility and it doesn't take much time to move them.
There should be no issue with the keel unless she has been grounded hard. If so, you should be concerned about water intrusion. It is more of a concern if it got wet and froze...not a problem in SF. The keel is typically epoxy encapsulated lead shot. Get a survey done for sure on a boat this size and complexity.
What is the engine in the 79? My 2QM15 (14hp) moves the boat to 5.5 knots at about 3000 rpm. That is fine for most uses but bigger is better if you are fighting a lot of wind, waves and currents under power routinely. If it is a 2 to 3 cylinder it is fine but 18+ hp would be better.
Typical issues to watch out for are bulkhead damage (see my project posted on this site) from leaky chain plates and wet decks. Look for water stains on the bulk heads. Have the surveyor moisture meter the decks or learn how to tap the deck yourself. Use a plastic handle of a screwdriver or a plastic hammer. Find a spot far from anything mounted or bolted to the deck and tap. You should hear a nice sharp sound. Go over to the chain plates and tap. This is a common wet spot. Not necessarily anything to walk away from the boat over, but don't be surprised if you hear a much duller sound in comparison.
Stains on the sole in the galley may indicate a leaky rudder stuffing box. Check the tabbing on the engine mounts. Smaller engines vibrate a lot and the tabbing holding the wooden engine beds to the hull was crap on my S2 and had to be re-affixed. Fixed ports and hatches on the 9.2A are acrylic and may be badly crazed. If the curved companoin way hatch is really bad it is a pain to fabricate and could easily cost a couple of thousand to fix. Don't be surprised if the mast lights don't work. This is common to most sailboats unfortunately. The water tank and fuel tank (you it is new) are aluminum and if they haven't been replaced are likely at the end of their service lives. Don't put chlorine in the aluminum water tank to clean / sanitize it. Believe me. I learned the hard way.
Check to see if it has a holding tank. The head and its systems may be badly out of date. Discharge overboard is illegal in most locations now. Holding tankage is likely limited. Mine is at the port bulkead under the L of the settee and is about 12 gallons. Two people can fill that in about 3-5 days. Pump outs are typically available and typically free. Just something to think about.
The tee shaped cockpit is great and not available on many boats of that era. Cockpit drains function well. Decks are plenty wide to move around on.
After initially looking at boats with a lot of fixed furnishings down below the open floor plan of the cabin has been great. In two years I haven't even set up the table as we eat in the cockpit. All the berths will fit a six footer. Something amazing in a boat this size. The vee is comfortable for me at 6.0 feet and the port settee forms a nice double. The hanging locker to starboard is great to have. Mine lacks a stove, but you can buy a burner top stove thing for less than $100 suitable for most uses. Storage on the boat is average for a 30 footer with one quarter berth.
Since the engine has been replaced, be sure to ask the owner if any work was done to the engine beds and to the exhaust. The original design lacks an antisiphon feature. Lacking it the engine can potentially suck water into the exhaust destroying itself. The danger occurrs mostly if you crank the engine for an extended period of time without it starting. You form a vacuum in the cylinders which can suck the water into the heads through the exhaust valves and exhaust.
Kenyon spars on my boat. Second boat I have had with them. No problems I know of except that mine has a fixed wire topping lift. Dealing with it is a pain as it hangs from the mast head loosely when the main is up and you need to tie it down out of the way somehow. Not a big deal. Just an irritation.