It is possible to implement containers such as gem bags and bags of holding in BG (to provide you with a bit modding history, they first did it in DSotSC) but the implementation is less than professional. The way it is done is to make an item that summons that invisible creature that starts a dialogue with you through which you access a store where the buy and sell percentages have been set to 0, allowing you to transfer items at no cost. The containers in BG2 work the same way but they skip the summoning and dialogue part of it. Anyway, I decided it did not want containers like these and therefore I increased all stacks and made jewellery stackable to at least make inventory management easier.
Antidotes are well worth the money. So are scrolls of slow poison.
Your characters really die a lot. When I played through the game, my characters rarely died and I did not powergame them in any way, but I did reload the times a temple or a spell or scroll of raise dead were not at hand.
-Echon