Soundtracks for BG:EE, SoD, BG2:EE, IWD:EE, PST:EE are now available
in the Beamdog store.
Since you added the blackguard I figured you might as well implement another class. The Alchemist, similar to a bard that is a jack of all trades master of none.
Solely the purpose of the alchemist is a supporting role, you can create fire breath potions or even lantern oil from icewind dale for example and other weaker healing salves using the priest tech tree in a similar way. (having slots and spells that represent the different potions).
At higher levels the alchemist can create potions of fire giant strength and invisibility potions even magic immunity. This would also make having a cleric not required for healing and having the whole "ideology religion" aspect influence your parties decisions.
Intelligence would be the primary stat, and if possible have instead of 4 or 5 weapon slots for the traditional fighter class it could be 5 inventory quick slots and 1 weapon slot.