I've read that mobgrief set to false prevents villagers from breeding, also making fully automated farming impossible. Is this the case?
Mobgriefing isn't set to false so this doesn't apply to the server either way :)
Oh, I thought so due to creepers being unable to blow up blocks. Is that an other plugin, or?
Stuff like that can be turned off separately in the server files. For example, all mobs can trample crops as well, which wouldn't happen if you turned mobGriefing off.