I don't know if it appears obvious to you, but reading your message from June 22, it seems quite clear that you put yourself and others in complicated situation with the hope of avoiding "awkwardness".
Tell Smitten Meetup Guy upfront that you are not interested. It will be awkward for one email and then everything will be clear for all involved. Right now, he's spending all that time thinking about you and composing poems, all in vain. His energy would be much better invested into someone else. Be kind to him and tell him you're not interested.
Engage Coffee Guy as much as you want, without having expectations of him replying a certain amount. If he's not responsive enough for you, drop him, but don't send complex silent signals with the hope of getting him to react. That's a covert contract and it leads to hell.
I'm glad to see that Other Meetup Guy has had the balls to be more direct because it will clear things up. It's now your responsibility to reply clearly to him and tell him that while you enjoy his company, you should be clear that you're not really looking for anything more with him. Like Smitten Meetup Guy, he will then be able to focus his attention where he might get what he wants.
Bonus: you'll be clear too and free to think about other things than people in whom you're not interested.
This might all seem very difficult to you, but I will suggest that you use the three gentlemen as testing grounds and just go ahead and be direct with them. See what happens. DBing is a learning experience and this sounds like a great opportunity.
I don't know your history all that much, so I'm not sure how much this avoidance has played a role in your life. I can tell you that it did mightily in mine up until separation. Then therapy came, with several readings and they all said the same thing: "Stop trying to be nice and be honest." I was so nice to a girl, years ago, that I got into a serious relationship with her (we even moved in) because I didn't have the guts to tell her I didn't want to spend my life with her. When I broke up with her, she was devastated, much more than if I had been honest with her at the beginning. We convince ourselves that we are being nice by not telling the truth, by avoiding to be direct and honest, but the fact is that we're hurtful to people.
Good luck and keep us posted.
M39 D6 D3 (at S) S 2014-09 D 2016-09
"You can't start a fire sitting around, crying over a broken heart" - Bruce Springsteen.