Without seeing the particular boat I can't comment on it directly. That said - if a boat, especially a well built boat like an Albin, has been cared for - I'd have no hesitation in buying it. And of course the price is usually impacted by the age so you're getting a lot of boat for the money!
The ONLY thing I'd be really cautious of is the hull. And this is a relative thing so don't freak out!
An Albin of that vintage is balsa cored. There is NOTHING wrong with this, but it does mean that your survey should spend plenty of time inspecting all thru hull fittings. Especially any that were added later, like transducers. Done properly (bored out, filled with epoxy and then drilled for the fitting) these points should never leak into the core.
Beyond that a survey should give you a great view of the overall "health" of the systems. And a boat like a 31 is nothing but a good foundation (hull) with a lot of add on systems. So find a good surveyor and let them do their thing.
To your specific questions - RobS will almost certainly chime in on the engines! Your fuel and water tanks will be aluminum. Not a problem for fuel. On the water side if anyone has put bleach in the tanks (common practice) the bleach will have reacted with the tank walls. So if you find little white granules in the fresh water system - that's what that is. The solution? Don't use bleach! (I use a commercial kitchen disinfectant to keep the water fresh and I use a carbon water filter when filling my tanks. A lot of city water has chlorine added)
Maintenance nightmares? I've had a 1997 28 and now a 2006 35. Nothing pops into my head. You'll probably find some kind of weird thingamabob that some prior owner did, but that again is a survey question. The engine hours seem a bit low, but not crazy low. Again I'll poke Rob to comment.
At the end of the day - if she was reasonably well cared for - you should be fine!
Good luck!
