Are communities unique? e.g. could you have a !gaming community on Lemmy.ml but have another !gaming community with different content on another server?

No, ::: spoiler spoiler Bargainer statues are located in the Depths. There is one in Lookout Landing that will show you the location of other ones. Their inventory increases the more statues you find (total of 6 I think) :::

No, they’re a lot bigger (although some are partially buried) - spoilers for Depths locations and items in this link

My favorite analogy is email- it doesn’t matter if you have @gmail, @outlook, or even disgusting ones like @yahoo or @hotmail, you can send and receive emails using the same protocols between any of them.

There is a text box just under the post with a "Post" button, at least for me: