Endings

Q v. R ending - is it a draw or can, without serious errors, the Q win? Also, is R and B against R a draw?

Depends on the position (there are always exceptions) but as a general rule of thumb: Q vs. R should be a win, though it is a rather tricky work; R vs. B should be a draw in the general case.
EDIT:
Okay, I seem to have misread the second part of the question. R+B vs. R is generally speaking a draw, except for a few positions studied by Phillidor.