Derivational Verbal Morphology

Sereer seems to have at least some verbal derivational morphology. So far, we've seen:

• -ir, a suffix that makes instrument-type nouns from verb stems (e.g. βɛʄ "to swim" --> bɛʄir "thing used to swim")
• -ir, a suffix that might be a reflexive (?) (e.g. χas "to scold, berate" --> χasir "to argue")
• -in, a suffix that could be called applicative, transitivizing, or something like that (e.g. gɛf "to break, explode (intr.)" --> gɛfin "break it", translation unclear)
• -ooχ, of unclear meaning (examples needed)