Get to know your bike, how it's put together, do some internet research on maintenance techniques (and save the website titles) and acquire some basic tool kits. Read and post in the BikeForums bike maintenance section, where there are some excellent posters with great experience in the old and current categories, and finally realise that the changes put on us by profit searching bike designers are a little tricky to come to turn with.
Ultimately, most of the problems you are experiencing with the losses of bike shop services in the area you live (wherever that is) can be met by personal knowledge. I drop into the bike shops in the areas I live or visit to see what they stock and what prices they charge, but about 15 years ago I learnt about mechanic incompetence, and set about learning my own stuff. I don't do any racing, but do long-distance randonnees and build bikes for my own use whenever the opportunity rises price wise and access to the equipment and parts I want.