I wasn't aware Open Kaillera did a peer 2 peer version, that is interesting and a bit surprising, if I get time I will at least take a look at it. The swapping feature you describe really belongs in Kaillera, it seems like something you would want regardless of the platform.
At this point the future of network play in Jnes is a bit of an unknown, I haven't removed it, but I have the impression very few people use it in Jnes, actually no one has mentioned it to me in quite some time! My guess is that it is due to other systems (MAME, N64, etc) taking most of the interest in online gameplay, but also kaillera.com has not worked properly in years so you can't get a server list for example (altho no one has complained about it). The open alternative kailleras being unofficial, I've been hesitant to replace the default client.
1) FDS support
2) Remap "save" and "load" to controller
3) Remap "save" and "load" to controller
5) Remap "save" and "load" to controller