As a Hunter, is it better to engage on PH with general startup topics or with industry topics?

If you just want a badge, go general. I f you want users, survive the industry critique.

I would say that if you have a very strong experience in a specific area (specialisation) and contribute to the forums (of any character), but can communicate the message very well, you can earn authority, so people will naturally follow your path.

And that doesn't apply only to specialised topics, but in general discussion. But of course, when you are an expert at something, let yourself shine and benefit from your strong position. :)