The answer is that you have to let your bike be your guide, not mine. Look at the bike, they aren't very complicated. What areas are you competant to work on? What tools are required for every nut and bolt of the stuff you can do. Some of these require quite large tools, and at required torque specs small tools may be useless, for instance I can't get my pedals off for transport with a small wrench, but the very largest is not required. If you don't carry a pedal wrench and had the guy at the shop use an 18" wrench on it, carrying a 6" wrench is probably not going to work. It is all comon sense, just look at the bike. Then you have to decide whether you can carry all the tools that are required for all the stuff you are able to fix. Are some repairs less likely? You can also, longer term, choose components with repairs in mind. Like threadless headsets, or fancy stuff like Phil BBs.