>Should I use the 4.9 foundation in all of these, brood and surplus honey?
> Can you extract honey from these small cells?
Yes. If you want to extract, I'd probably do wired. If you want to do crush and strain or cut comb on the honey, then you might want to do unwired and do 7/11 because it's cheaper than small cell, and is a size that the queen doesn't like t lay in.
> Should I stay with 10 frames instead of using 9 for the honey supers?
Until they are drawn. If you extract them and have drawn comb, 9 is ok.