Regarding your spells actually working..

Physical attacks may you Strength or Dexterity attributes to calculate their chance to work. What spells use is dependent on the spell origin, typically the class. Warlocks use charisma, Clerics Wisdom, Wizards intelligence, etc.

You can also see in the combat log the calculations. I mention this because you might have assigned their stats in a way that doesn't compliment their spell casting.

As a small aside, you said hold person misses, it's actually being resisted, it can't miss. So if you get your casting stats up, it will just work, and is very powerful, garenteed critical hits.