Minions should be soloable (like regular mobs but with skills).
If this is the case, it would probably make sense to try to balance these a little bit for different classes.
At the present time, being immune to skills seems to give a HUGE advantage to melee classes, unless I'm mistaken. (I'm a relatively new player, so I might be misunderstanding melee mechanics.).
Would it make sense to have some minions immune to physical damage and some to skills? That way casters at least have a fighting chance at soloing some minions. As a lvl 65 wizard, I can't solo a minion without using lots of health pots or leaving the fight to regenerate health, because even with the newly reduced dmg of bleed, the bleed effect will still kill me long before I can do enough physical dmg with a diamond hoe.
Also, if these could despawn after a while, that would be awesome, because my place is rapidly filling up with them (and as a wizard I don't really have a feasible way to kill them) so my house is rapidly becoming unlivable.
Anyway, really nice job overall, just wanted to give the above suggestions!
TL;DR: Casters should have a way to kill minons, minions should despawn.