Well, i know its late to reply to such post (that is almost 2 months old) but if you still have these issues then here are my suggestions problem-wise.
1. For 802.11, i guess the only feasible option is ad-hoc network. It works for me at least.
2. Yes problem is with your IPTables, you need to setup proper routing between both wlans.
3. Per node sub-netting may not work under certain conditions, consider the case you are moving from one node range to another, the new node will not work for you till your DHCP lease expires and you get new ip from new node. If you try to use same sub-net for all nodes in per node sub-netting (as you mentioned) then there is a possibility that address assigned by old node is assigned to someone else in new node, causing an IP conflict.
4. For per node sub-netting using same sub-net (10.x.x.x) for all nodes, you will need separate DHCP servers, otherwise single dhcp server will do.
Shaheryar S. Sheikh