1. yes, specifically if the 'discipline' is 'people who care about bikes and are not dicks'. As for what type of bike, well I have my favourites, but other have theirs.
2. it won't. but my idea is not a normal bike shop... maybe it will. who knows? but it won't *have* to.
3. no. But I know shops who will and I'm happy to refer...
4. fixed that for you, and see point 7.
5. not yet, which is why I don't have my own shop
6. yes, too much! which is why 3 - and 1. Happy to fix/restore golden oldies, but it ain't cheap.
7. in the long run it is, all part of point 4 - winning the business you want, being able to decline the business you don't want.
I guess my main thrust is that there's no point trying to compete on price or range - CRC/Wiggle/Pushys/MTBdirect all have a small shop beat hands down there. So a new shop needs to really kill it on service, offer something different, specialise, carry something unique, provide a service that isn't currently offered in the market. Not easy - and not very profitable for a long time. I would also work at staying small - I don't want to work too hard, after all!
In other words, I'd personally be happy to run a part time garage operation - only reason to have a shopfront is to carry certain brands of parts without having to do an international mail dance to sort out warranties. Anyway, check back in 5 years - I might be in a sweet little space near some trails and a good coffee shop, wrenching, chatting and having fun
Back to the OPs post, yep, I think a brick and mortar shop can be profitable, and this thread has some golden ideas (mine are probably a little screwy, but other posters have given some absolute gems).