When Should I start #2.
First, I went from a Goldberg falcon 56 mk II to an extra 230, so don't let anyone scare you.
On the warbird thing, it probably depends on a number of things, the first being your comfort level. Second, are you talking really scale or a sport plane? A really scale warbird will tend to have a high wing loading, which is best to ease into. A sport version, such as the new H9 mustang, flys like a high performance low wing trainer but looks much better.
Look around at your local field and see what interests you, then decide.