you cant kill the bird by clipping tail feathers, but you may cause severe bleeding if yoiu cut too short. many birds have problems with tail feathers, mine didnt really get over his problem of breaking his tail feathers until he was about two years old. it is perfectly normal.
HE/SHE IS MOLTING!!!!!!!!! Thats wen the brd losses feathers.I think it happends like once a year just dont kut the feathers unless clipping its wings!!!!!!!!