If it is indeed in very good shape, all you need to do is clean it well, repack bearings (hubs, bottom bracket, headset) with grease, remove and grease stem and seatpost, replace cables and brake pads and tires, check/correct spoke tension and wheel trueness, lube drivetrain. You will spend some money on tools, so no reason to spend more by replacing things unnecessarily.
Don't skimp on the correct tools. Bikes have a lot of fine threads and small alloy parts, blundering around with pliers and an adjustable wrench will do damage.
The only bearing you can reasonably replace with a sealed unit is the bottom bracket. It won't make any difference to performance.
I don't know what the bike is worth now, but it will be worth no more than $100 if you powder coat it. Painting or powder coating devalues bikes, unless the original paint is truly trashed and the repaint is part of a high-quality restoration with factory colors and correct decals. If you don't like the color, probably best to sell it and buy a bike you like.