Trusted Reporting (Quora feature): Trusted reporters (who are not moderators but designated power users) can insta-collapse an answer or comment: Moderation at Scale: Distributing Power to More People by Marc Bodnick on The Quora Blog. They cannot delete them though.
Moderators who are in-house Quora staff are also Quora users (all in-house staff seem to be), and they can still upvote and downvote. Their upvote or downvote may count for more than others’, just as mine likely counts for more than J Random Quora user’s: their impact depends on the user’s PeopleRank, and in-house Quora staff are likely to have high PeopleRank just by virtue of seniority, if not office.
There may or may not be moderators who are outsourced; we don’t know. If there are outsourced moderators, we do not know whether they are Quora users as well, and whether they can accordingly upvote or downvote.
But like I said, the capability for insta-collapse, which trusted reporters have (and which I’d assume moderators have) has far more potential to, as you put it, sink a proverbial ship than a mere downvote does.