I don't own an imac (I love my zoozone too much
If I didn't have it I would have a 4-5 level imac though for all the hams) but my cousin does and I looked after her ham for 2 weeks so I have some experience with them.
I think they're great cages - the only thing I don't like is the fact that it has a small door on the front..but, if the hamster is nice and tame and comes to you then I guess it doesn't really matter - I'm just used to the whole top opening because of the zoozone and bin cages.
I think ideally you should tape the circle things on the top down otherwise the hamsters might learn to open them.
I don't understand the question about the water bottle? It just fits like any other water bottle would to a wire cage..?
When I looked after her hamster she didn't chew the bars much, she did occasionally but I guess it just depends on the hamster.
Oh, also, if you have two syrians in there (with it seperated of course) it's hard to fit a decent sized wheel in the upper levels..I know a wodent, comfort and rolly wheel all fit in the bottom level but only the rolly fits in the other levels I think.