Jay said:

Regarding your second request, you can still use forum tags even with the advanced editor in place. Feel free to build your nested quotes manually if the editor makes it difficult to accomplish exactly what you want.

Ahh, thanks. Actually, I probably should have tried that by now. I guess I was stupidly assuming that entering quote tags would automatically create a preview.

Otherwise, the spacebar=line-skipping problem is not one that I get too often. It's happened to me once more since I posted this (again when a quote preview was at the top of the text entry). It's not a difficult problem to deal with but it does make me disoriented for a fraction of a second. :)