My question is: can this harm the stick or shroten the life of the microswitches?
The answer is, that there's no reason at all why it should shorten the life of the stick. However, they have a pretty short throw to start with. They're a great stick for use on fighters. I'd just have replaced the switches with standard cherry (red) ones. not with lever ones.
Best Regards,
Julian (Fozzy The Bear)