The old gaskets are probably fine. You'll know soon enough if they aren't. It will stumble or run rough if unmetered air is making it into the engine through a vacuum leak at the intake. Leaks can be found pretty easily in some cases. Post up if you have issues after you get it running.
The oil in the intake is probably no big deal. All modern cars have the crankcase ventilation run into the intake track. Since blowby is a normal byproduct of internal combustion engines, it is normal to find some in the intake track. It eventually/continually makes it into the combustion chamber on all engines. The PCV system was one of the earliest emissions
control components.
Too big a deal is made over oil usage online. It takes a lot of oil usage to cause issues. I'm talking a quart every tank or so. It is a huge deal if you are too stupid to check/add the oil as needed, and it would piss me off to have to add lots of oil to a new $30,000 car, but a quart every few thousand miles wouldn't bother me. I've added over 100 quarts of oil to my 97 F-150 over the last 150,000 miles (currently has 335,000 miles). At a quart every 1000 ish miles, there have been zero ill effects, but it gets checked and topped off as needed. The catalitic converters are original as are 2 of 4 O2 sensors. Those were changed due to failed internal heaters.