Keru hasn't been a monk. There have been references here and there to him showing interest in another crewmember (for instance, the end of Sword of Damocles
implies he's having a romantic rendezvous with someone, though the gentleman is not identified by name), though nobody's gotten around to developing that thread in detail.
There are plenty of LGBT characters in Trek Lit, many of them alive and well if not recently featured in the books. You can find an extensive catalog of them in this earlier thread in this forum: