Just my own opinion but don't overly stress yourself out about it. One thing I learned over the years is that most players get way too concerned about all the little piddly little details. Unless it's a major repair or something, do the work yourself. It's only wood and metal and worth your while to grab some books from the library and teach yourself how to service your own guitars.
Especially simple stuff like truss rod adjustment and intonation. You can't trust a guitar shop unless you've built up a relationship with them and know who the guitar tech is and what experience he has. I mean, I've been living with my main guitar 24/7 for a coupla decades... there's no way I'm taking it to the local Acme guitar shop and trust that it might be some student working on it, or a salesguy doing your intonation between customers.
As far as what strings to use... change em up every once in awhile and live with a different guage. Try it out for awhile and then switch and see how it effects your playing. It took me years to figure out that I need 9, 11, 16, 26, 36, 46 for most playing. But it depends on the type of music you're doing too.
Lighter strings are more twangy and trebly sounding and easier to go out of tune from improper use of your fretting hand (ie, holding one string down a little too hard will make it slightly sharp.) Heavier strings have more body.
If you're doing shred, go with lighter... if you're doing blues or chord strumming, go with a heavier guage.
