I've always though of {selja'e} as being a somewhat looser / less strict relation than {rinka}, as if it was something like {x1 .a lo selpau be x1 cu rinka x2}, so that one can say {lo nu carvi cu selja'e lo nu mi na klama}, where the connection between the two events is not clearly explained, and where it seems that "lo nu carvi" is not the only factor that have determined the event {lo nu mi klama} not to occur (another plausible factor could be "mi na djica lo nu mi se carvi").
But this impression that {selja'e} is looser than {rinka} is perhaps subjective, and maybe {rinka} can be used just as vaguely.
But, isn't this second example (that with {kacna'u}) what {nibli} is for? I thought that banzu-nu (the version of {banzu} that parallels {sarcu}) was the event equivalent of {nibli}."banzu" is not the same as "rinka". ro da zo'u da banzu da .i ku'i na ku ro da zo'u da rinka da .i la'a no da zo'u da rinka da .i ro da poi kacna'u zo'u lo du'u da pilji li vo lo kacna'u cu banzu lo du'u da pilji li re lo kacna'u .i ku'i pe'i lo du'u pilji li vo cu na rinka lo du'u pilji li re