Whatever plans were once made for the refugee center have long been abandoned.
That said, i-am-erk has been busy populating it with NPCs, so I think he has some current plans. I know that Jenny Follete is going to be expanded to provide additional security for the center, in the form of makeshift turrets and such.
I intend to add a facilities manager who goes around and repairs damage to the evac center (and another for the Tacoma Commune and others for any other factions that gets bases). The code support is not quite there, but I’ve gone from “boy that would be interesting if it worked” to having all the major pieces in place and now needing to do a lot of work to hook them together.
If you want to co-ordinate with i-am-erk, I’m sure he’d be happy to have another person writing NPCs for the refugee center.
If you don’t, I think your ideas are pretty good. Unless you’re really attached to the Free Merchants, you might want to write your own faction with their own base. There’s a list of proposed factions on github, or you could come up with your own entirely. CDDA has languished for years with only the Free Merchants and the Old Guard as factions, but that’s never been intentional.
obligatory link to the Guide for 1st time contributors (it’s been nearly a day since I last posted it). Pay attention to the newly introduced update_mapgen functionality, because that means you can implement your own mission start (and mission end, and mission fail) functions in JSON. Take a look at data/json/npcs/missiondef_free_merchants.json : all of the Free Merchants mission starts and ends are now in JSON instead of C++. It’s a huge increase in functionality for JSON only contributors.