Thanks for your posts, this has been awesome. I'm very appreciative of folks taking a few minutes to share some info / insight / experience.

I've looked around my area for decent new bikes but there just aren't a whole lot around, and I don't want to 'settle' for just some bike because the selection is slim.

So I'm going the route of just fixing what has to be fixed right now. There's a Shimano Deore 1x10 groupset that I've been eyeing that looks good, but I don't know if it would work on the rear freehub that came with the bike. The bike came with a 3x7 setup, does that mean only a 7 sprocket cassette would fit, or would an 8,9 or even 10 work? The dropout is 135mm, which would seem to be enough room for one of the larger cassettes, but I'm not sure.