Yes, it converts links so they’re clickable but otherwise all the text is assumed to be just text. Not impossible to change of course, but just not in a near term release.
Well, there’s not a direct hook. There is API access to the forums, so you could build your own UI. I believe the HTML will be escaped, but you could unescape it.
You are getting into a lot of work then though. I’d probably be inclined to use a full featured forum for that aspect of your business instead.
HelpSpot’s is really optimized for basic interactions with people who come by once in a while for support. If you’re having a more intense relationship via the forums then a full featured forum with profiles, signatures, etc can add a lot. It’s very common for customers with those needs to use that type of tool and then link to it from HS’s portal.