To clarify, just checking these things doesn't do anything. Checking them, knowing what's wrong, and then taking action is what saves you a ton of money.
Well that is one of the things I have no idea about. But maybe it depends on the type of mechanism you use? I can't imagine it would be too hard with my bike.
Yes probably, the last time i attempted this was with my old bike, which had one of those horrible 3x8 shifters. I guess it would be a lot easier with my current 1x12
Mainly to get to work (10 minutes), but also all other short ways and occasionally getting out in nature.
As soon as money allows it, I'll get a better one though. It's used and I mainly bought it because the seller was close to where I live, but I need a larger frame and I want more modern mechanics, e.g. disc brakes, overall.