as to the shutter button -- does it work? does it fall off? if answers are yes and no, then it's probably up to spec.

The film counter? Well, it's a cheap plastic thing, if you can get it to work by tapping, it's probably not worth the cost of sending in for exchange. sort of another feature, along with light leaks.

this is why i buy all my cheap plastic 35mm cameras at the thrift store...hands-on inspection.