You can only buy the accent skills once, after you have bought them all the accent points become useless, also when i got to zone 300 and unlocked wind rock and wind marble only the rock shows up in my supply tab, i cant make the marble even after buying the research.
The fact that the tavern can only produce one group means everyone not in the group just gets killed pretty early on and i have one party that goes out and clears the map and restarts. taverns need to be able to set up multiple groups