@AishesChayil:
I don’t think you are right about the Kohen having to divorce due to just a ch’shash, although I still may be wrong about that. I would imagine that if the Kohen is truly worried about infidelity he should investigate it fully, but I don’t think we would actually make him divorce her. I definitely do think you are mistaken about there being a Mitzvah for a Yisroel to remarry an unfaithful wife, however.