Rims I'm not too worried about because original stock rims are normally very strong and this is still made in Japan too so no doubt on its durability. Anyway even if they got bent, I already got the 5Zigen 15' so no bother. This original rims also can easily find on sale in the Swift club, and they're selling them cheap.
Maybe can. Yeah I also never seen a 1.5MT version to be honest!
Is like the usual saying where people tend to say no aftermarket wheel is stronger than those stock wheels that came with the car.

Your set of 5Zigen is also an original set from Japan?
If only there are normal Swift 1.5 manual being sold here, it would be quite a bargain for a car at that kind of price. Imagine, for half the price of a ZC31S, it can handle well with some suspension upgrade and still comes with a manual gearbox that is no slouch compared to the 4AT variants.