Yes, the LBS I shop at most often, and where I bought my bike, is not nearly the closest to my house. They are worth the trip. And they're close enough to other stores that I can usually make an errand-fest out of it.
"find the old guy" :D that's what I do when I need girly stuff like make-up that I know too little about, find some kindly matron who will tell me what I need without making me feel like a dork :p
I know about feeling like the bike is tiny. I felt the same way first time I tried a road bike, it was like handling a toy. Remember mtbs are built for really hard riding, jumps and landings and stuff, so the frame has to take lot more than a road bike. Honest, they're plenty strong. Little miracles of engineering! :D But you do want good wheels.
In my perfect store, the salespeople notice me as soon as I come in, call out "Hi! Let me know if you need any help!" and go on doing whatever they're doing. I love that.