Add a poll system!
It'd be very cool to see and use!
Are Mastodon polls a native feature of ActivityPub or are they specific to Mastodon?
I've only seen them on Mastodon. I don't know about Pleroma or Misskey or the likes.
yes
The tricky part is implementing it with ActivityPub - could probably use the Likes as votes somehow, but you also want to be able to enforce things like only one vote, or multiple votes, etc.