For your Sorcerer L5 spells, Hold Monster is fantastic. I would prioritize this. Elemental Adept: Fire Feat will make it so enemies cannot resist your fire spells.
I like Savage Attacker for Lae’zel if you are going to continue to use Strength potions/items. If not, then boost Strength. Continuing on the potions/items route is viable.
Boost Shadowheart’s Wisdom to 20.
Boost Astarion’s Dexterity to 18. It is so useful for all of his skills. Note that Titanstring Bow adds both strength and dexterity, so boosting dexterity will help there too.
