It's a good cage
Agree with the point about it being fiddly to build and move - the pros and cons about it being a "knockdown" cage. One of the biggest pros though, IMO is the large front opening door.
Lucky dwarf hamster. However it is very tall for a dwarf hamster and there could be some fall risks if the hamster scaled to the roof height or monkey barred across the top. Ideally it needs a full level for a dwarf hamster - or no items at floor level that can be landed on and cause injury - just lots of substrate - this would leave a lot of the floor area empty and toys under the shelf.
Unusual for a hamster not to like a wheel - have you tried a flying saucer? They nearly all love those.