Hey, sorry for the late response, i just got the notification, while briefly looking into the plugins, im already interested in 2/4 plugins you listed here (mcmmo, minable spawners), gonna take the time to review them all later at length and i'll let you know.
Also we already have some of these features although, some factions have been approved/allowed to claim big amounts of land cause of A) Their location B) Their needs C) Their security etc.
And we have already a plugin that saves people's inventories on death, its called saverod, now we could setup a poll comparing these two plugins/ways for players not to lose their stuff although saverod seems to be enough for now.
I have already made a possible list of stuff we can add on a store like ranks, crate keys etc, and i have found a good store plugin although i need to look more into it before we setup an online shop. Also we already have donator ranks setup with perks depending on the rank's level/worth