I was hoping, since they love to climb, that I could place a Sago palm Bonsai in a section of the sand side to make it look more like a little island for them.
I assume I'd have to bury it inside of it's little pot so that it would stay a bonsai and not grow out of my tank

Would it be okay to bury a small amount of sand over it, just enough to make the 'pot' look invisible? I assume drainage would be fine with the pot buried, it could just filter out through the sand which would lead down through the tunnels the crabs will be digging.
Also, even though it will be separated by glass, there's a chance some brackish (salt) water may occasionally be dragged near or over the plant by the crabs, would this hurt it? (I can't imagine much of it getting over there unless they find a way to dig through the glass..lol.
I'm a total newb to bonsai so I will of course be doing some research on how to care for the particular plant I want.
I was thinking of something like this, unless anyone can point a better type of tree/plant out to me:
[img]https://a764.g.akamai.net/f/764/16742/1h/www.1800flowers.com/800f_assets/images/flowers/images/shop/catalog/3430z.jpg[/img]
Thanks for reading!
- Sarah