I think I answered in another thread: I found that wheedling, playful bargaining, and being a good customer changed my LBS's tune. At first, they said they wouldn't work on the motor, but after I'd had a few hundred bucks worth of maintenance and upgrades done, they were like, "Well, yeah, we're Specialized dealers." (That may have changed between when I bought the bike and when I asked the second or third time. Maybe they weren't a dealer the first time I asked.)
As for assembly, I do recommend having someone assemble your first bike, even if it's just the pedals and bars. (I might not for my next one, I might just have them check it after the first 100 or 200 miles.) This is a great way to build up your reputation with the LBS, too: I think it was over a hundred bucks, and part of the reason for that is they will look at stuff I wouldn't know (at first) to look for. This is true of routine maintenance-- every third time I bring it in for new brake pads or whatever, I might say, "Just look it over," and have them charge me a bit more. Ask them what they did, what they checked, and make notes, even if that means just dictating a few items into your phone when you leave the store.
That is how I found out my main suspension bolt tightens from both sides, not just one! And it was loose, could totally have fallen off.
Fortunately, having started at this forum, I expected to spend some money on maintenance-- both routine and otherwise-- and I set aside money for it. I also assumed there was a lot about my bike I didn't know that my LBS probably did.
