This is a personal thing, but I find it much easier to get familiar with an engine when I can tinker with it on a test stand. Once it's in a model, it's always harder to work on, and you greatly increase the probability of damaging the plane.

Why not invest in a cheap test stand? (~$20) Most of them are adjustable enough to take almost any engine you're likely to own in the next few years.

For break in, you should follow the instructions reasonably closely. That said, it's worth reading this thread if you want to know more about ABC engines:

http://www.rcuniverse.com/forum/Tape...1850473/tm.htm

I wouldn't be too worried about using really high oil content, but it helps to understand what's best for a tapered bore engine.

Matthew