The hide looks pretty good I reckon, as long as he can get in without struggling. My lot like tight spaces
The tank is looking lovely. I don't think you *need* to add anything else, but you could add some taller plants or perhaps some slate or a piece of wood on a slope or something, he might like to climb about, and hang out in high places! I think you've got the basics wonderfully, everything you add now is more adventure!
The filter looks like it's creating quite a down flow, or is that just the pic? It might stress him if it's too fierce? Only other tip would be, you probably could take some of that sand out, deep sand needs swirling round quite a bit to stop it turning anaerobic and getting toxic. Up to you though, a good swirl around a couple of times a week, or every time you go in to de-poop will do the trick to keep it fresh