Where do general researchers make general discussions, online?
A lot of them are indeed on Twitter, but as usual with humans, cold asking them is probably not appreciated by many. What you can do, though, is simply follow them and see what they're saying, as they're saying a lot. You can find the people you might want to follow through hashtags indeed - the ones probably most open to your ideas will be talking about #OpenAccess (or #OA), #OpenScience, #ScholComm, #ICanHazPdf, off the top of my head.

Something that might work better is addressing them in real life. I'm told they mostly hang around universities, so you might try and approach people there to ask whether you can have five minutes of their time.

PS. I don't think there's a way of messaging on Stack Exchange, but if you make a Twitter account and share your username I'd like to contact you.