Oh, In the first era it's not possible to get to Bumbleland. The idea is that you would have to have a guide, but I guess I also made it feel like it could be done in theory. The seaweed is on the beach where the seaponies are. It's not in a treasure chest, there's a piece of terrain you can interact with. Buffalo territory is also not accessible in the first era. The bunny house should not have soft locked you, so I'll have to fix that.