Mostly Maren answers questions on lp, and sometimes me.
I was tempted to send an email about this topic yesterday, because I'm really fed up with the spam on lp answers. I received 2600 spams yesterday, and 3100 spams today (three thousand, yes), which is a bad day.
Overall, My junk folder contains about fifty-one thousand (51000) spams from launchpad answers only, since I joined to ask questions in december 2015. I crafted my .procmailrc to filter out most of the spam automatically, but recently more and more is escaping, since the spam is now in messages rejecting (marking as "invalid") legitimate (and spam) questions, or designed to post a question that *looks* legitimate (like "why ubuntu no virus") only to answer it quickly with spam answers, and I cannot filter that efficiently.
For now, I'd say the launchpad answers section is not usable.
What worries me most is that spammers have started to invade the "bugs.launchpad.net" section, which means that if the launchpad spam war is going to be lost there too, we will have to move to another bug tracker (maybe the gitlab one ?).
Anyway, to answer you, for the functionalities, ideally we'd need: -> a search in already existing questions before asking one -> automatic email updates for a group of people answering questions, for any activity on questions; and email updates to the people asking questions -> status of questions (open/answered/solved/invalid)