> I'm just not sure how to bind and seal the seams of the pouches.
I made my own camera pouch too. WP/B fabric outer, then a layer of 5 mm CCF, then a spinnaker liner just sewn to the outer at the top.
> Can you sew closed cell foam?
Yes - best done with the Lycra-clad neoprene, but possible.
> Would glue work? What type of glue would be best?
Yes. Contact, Gorilla, PU sealant...