Hi Kiki. Chinese hamsters are wonderful, but they are not for everyone because they don`t particularly like noise or rough handling. If you are getting a single Chinese for yourself, he can have a shelf, ramps, branches, climbing accessories and basically enjoy his cage.
Think Mouse....and you have a Chinese hamster only with a shorter tail!
1. If you have wooden toys/accessories, a mild chlorine bleach solution (follow instructions on the bottle for usage) or get a baby bottle sterilising fluid and soak them as per bottle instructions and properly air dry outside for a few days to a week. Any bark covered wood might fall apart though so only bare wood might hold well.
2. The cage size doesn`t really matter, but your right that they do better with plenty of hiding places and egg box/toilet roll tubes and anything other dwarf hamsters will enjoy.
3. Is Darwin a Chinese hamster? If he is, then you will be used to watching how a Chinese hamsters reacts to things.
4. A Bin cage is fine as long as it`s well ventilated. Meshing the front is a good idea rather than just having the lid meshed.
The diet should be considered before getting your Chinese. They are one of the diabetic prone species, but that just means they can`t have `added` sugars in their hamster mix. There is no need to remove corn, maize or peas. These are all part of the nutritional mix. If you want treats, look at small fingersnail pieces of raw broccoli, cucumber, carrot and a small amount of cooked brown rice.
Hope this has helped a wee bit. x