I finished my first run the other day and had no inventory issues. I did stop picking up every single thing not bolted down about halfway through the game and still ended with a surplus of 25k gold. You can select multiple items and send to camp/stronger party member or add to wares for quick sell. I was a low STR sorceror so just sorted by weight and sent it all over to lae’zel whenever I was carrying too much. Didn’t really go out of my way to go to merchants