I am looking into getting more serious about doing my own automotive repair and maintenance, and am working toward gathering the appropriate tools. However, I am admittedly can be a bit of an organization nut and hate clutter; I do not want more tools than I will actually use (even if only rarely). Specifically, I have the following questions:

 - What is the advantage of having 1/4", 3/8", and 1/2" socket wrench handles versus having a single handle and adapter? I believe sockets from all three sizes may be used in a vehicle, but is there a need for three handles or will a single handle with an adapter work fine?
 - On a related note, is there truly a need for a fixed wrench set or not? I know I tend to turn to socket wrenches, probably due to their versatility.
- What requirements does one need in a multi meter for diagnosis? I am looking at very cheap one (I certainly do not plan on getting to deep into an automotive's electrical system); will such generally suffice even if it is not 100% accurate?
- What drive size is recommend for a torque wrench and breaker bar? 

Obviously, I realize I could probably get some answers based upon the specific vehicle I drive at present (91' Astro); however, I would much rather these tools have wider usage. If it does help, I will almost certainly be working exlusively or primarily on older, North American vehicles.

Thanks much.