I think there should be a button for grounds to decide wether shaman items can or can not collide with it.

well what do you think? also one that only shaman can go throguh and it will look like dis:

Shaman collision:

Ground with a feather design on it and feather cant be hidden!

Shaman Item Collision:

The ground will have a little cloud like look to it! It cant be hidden.

i realllly dont understand...aat all

I don't quite understand. If you mean for the ability for shaman-spawned objects to collide with a certain ground type or not, there is.

If you mean for a CERTAIN shaman-spawned object not to collide, like, for instance, this trampoline ground won't collide with a long plank, but will collide with every other object, then still no support.