Great write-up. I would like to piggyback on the "Map Spawn Rates and Mobs" issue with my complaint that in Reboot, the mobs in Masteria (along with other regional content) appear to not have their HP/EXP scale by the usual Reboot multipliers. I feel like changing this could help with content engagement, since otherwise the maps are doubly useless for training in Reboot.
I think at the very least, the drop rate for Common familiars should be boosted back to the rate when the revamp first happened. Strictly speaking, the real problem with that drop rate was the high rate of Epic familiars, and nerfing the drop rate of all familiars across the board just to fix the Epic drop rate was a terrible solution. There shouldn't be a problem with raising the drop rate for Common familiars back to what it was, and having easier access to a large amount of Common familiars would improve familiar gameplay in all aspects (collecting for badges, fusing for rank-ups, extraction for booster packs).