Biplane design questions

A few questions, for those in the know:

Both of the radio-controlled biplanes I've owned were designed with the lower wing at a higher AOA, so that it stalled first. They also had the upper wing farther forward than the lower.

If the lower wing stalls, the CG will be a little on the aft side of the upper wing. Wouldn't it be better for the upper wing to be behind, so that the CG is a little more forward? I've seen some biplanes like this, such as the Beech Staggerwing, but most seem to have the upper wing in front.

While my R/C had the ailerons on the lower wing (my other one had no ailerons), it seems most of the biplanes have them mounted on the upper wing. It would seem to me that the lower wing would be safer, because you'd have a harder time tip stalling that way - the upper wing would be able to keep flying after you tip-stalled the lower one. Why is it the other way around on most biplanes?

Also, it would seem only necessary to put washout in the upper wing, keeping the lower wing flat. Is this the case with most biplanes, or do they put washout in both the wings?