Quote: "Are they good for badminton practices or small tournaments? "
Probably, generally for stuff like Badminton it's good to have a pair of court shoes you don't wear outside - some courts are quite fussy and ask for non-marking shoes and naturally, court shoes don't mark, looking at the bottom, it's possible they'll mark - but if where you're going doesn't mind, then that's nothing to worry about. I've got myself a pair of Hi-tec Squash shoes for doing Badminton and Squash (as my local sports centre
is fussy)...speaking of all this, I really ought to continue going to the court.
http://www.sportsdirect.com/hitec-squash-classic-trainers-mens-176001
As long as you're comfortable and can move around in your shoes well, then it really ought not matter whether they're designed for a particular sport or are scientifically optimised with little rockets attached to your feet...unless you're racing, then rocket propelled shoes ought to give you an edge.