1. Can you equip the Great hammer

2. If can equip does it give better bonus than start

I don't think you can. The only use for the hammer is to craft and using a great hammer for that is a bit much. Maybe in the future as a weapon if combat gets added in. Hope this helps.

I  think you can..., And if not hope it will be later in more updates

yes you can equip the GH but the stats will be still the same