Is there a way in SMP to share progress/money between two or more players? I want to play with a friend, but we don't want to each make our own towns.

No direct way, you can skip the tutorials though (don't need separate towns just talking to the npcs) and for money sharing atm you can buy/sell salt since it ships for its cost. I do not want to add teams, I want to keep things open ended. I do plan to add like a bank in the future though where you could deposit money and share it.