Looking good. I always put less substrate around the wheel to stop it getting all caught up and while spinning it makes a squeaking noise. Also as your wheel has a stand you could have a much bigger sand box and have the wheel stood in it.
Personally with the bottle I'd have it on the bottom shelf initially as its likely your ham will stay on the bottom shelves for a bit until they're settled. You could add a second on the full shelf or permanently move the bottle from the bottom shelf to the 2nd full one?
Not sure how youre going to add the bendy bridge at the top. Unless you're on about having it from (top) floor to ceiling.
The wooden house at the bottom looks big enough, if the gaps are a tad small you could modify it and make them slightly bigger.
Initially I'd leave the sand box as it is. No point adding loads of it's not going to get used. If (s)he loves to have a sand bath chuck loads more in. More the merrier. If it's only used as a toilet maybe it'll be ok. See how your ham reacts and go from there.
Rather than use a bendy bridge you could get a bigger box for nesting and have it fill the whole gap at the top. Have one hole at the bottom to get out and leave the top open so (s)he can get to the top shelf that way. Add some wooden or hang loofah chews from the top and voilą
