The Grampian was a good quality boat. If it has no soft spots on the deck, then I would say its a good buy. Your "cons" are not big deals.
It will take less than a gallon to put on one coat of new bottom paint; less than two gallons if you need two coats. Assuming you will be using ablative multi-season paint (highly recommended), at about $150/gallon, its not a big cost. That stuff can be put right on top of any existing paint; no bottom job needed.
Roller furling for a boat that size will run about $500 for the unit/foil, and another couple of hundred maybe to modify your existing sail. Some units may require that you replace the headstay if the length of the existing stay can't be adjusted to accomodate the furling unit; you may need a new, shorter, stay installed. This is the single best upgrade for single or shorthanded sailing you can do.
Outboard engines on small sailboats are a crapshoot; if well-maintained, they can last for twenty years. Often, these types of engines get very light use. If I put 20 hours/season on my engine, that's a lot. I only use it to get in and out of the marina and out to the harbor. Two strokes have few moving parts to wear out and are more tolerant of mistakes and less than stellar maintenance than their four stroke cousins. You will find many people who consider the two stroke engine to be a plus in this purchase.
No stove? Buy a Coleman camp stove for fifty bucks.
Other boats in this price range that should be available: the Oday 23 and 25; the Catalina 22 and 25.