You don't necessarily need to know where your map goes. It helps, sure, but most people will help you figure it out if you can't find it. Plus there are sites that tell you all possible map locations so it shouldn't take long to figure out, and most parties have several maps to run anyway, so you may have your first map figured out but you can't have your second/third/whatever map figured out until you've done the previous anyway.

As for loot rules it depends on the party. Most of them will do Map owner needs everyone else rolls greed. So if something drops the map owner gets first dibs, and if they don't want it then everyone else fights for it. Some parties do free for all though where everyone is allowed to roll need.