It may break soon or not. Think of Scrödinger's Cat except instead of it being a cat, it's a microSD card and it has higher chances of being dead/corrupted due to it coming from China.
I don't think so. Mine has been working perfectly smoothly till so far. For DS games, it's good choice i think.
As long as you don't have a fake microSD, everything will be fine. That is assuming your microSD cart has no problems wih formating.i got the r4isdhc.com carts and changed it to boot RGF YSmenu by default. would i encounter problems with it down the road? i'm currently using it to play Phoenix Wright haha.