Ought not (ou chrē). The only use of this old impersonal verb (from chraō) in the N.T. It is more like prepei (it is appropriate) than dei (it is necessary). It is a moral incongruity for blessing and cursing to come out of the same mouth.
So to be (houtōs ginesthai). “So to keep on happening,” not just “to be,” present middle infinitive of ginomai.