Id say keep dollars as an optional currency it makes it more fun that way.
Exp loss sucks plain and simple. Im a cautious player so it deters me from going out on adventures and exploring. I think the best would be permanant stat losses until you get to an infirmary to fix up and item durability loss that is repaired using scrap metal or other materials and not money. Crafters could make repair kits which they could charge cash for or other materials => boosting player driven solutions and making the game feel more interactive. Those repair kits could get better and even provide some durability immunity for a duration giving another niche role in the intricate crafting system.