Actually that part isn’t a big problem, I think. I intend to move to the US soon regardless of how the relationship works out, and if it does work out, the city she’s in has many options for my field of work.
Oh, dear…
She sounds like a “relationship junkie” to me. I have a feeling that since you are now older that you’re going to have a little clearer picture of what she is (and isn’t) when you see her. Planning a trip to a neutral place won’t give you a true idea of the whole thing - anyone can go to Hawaii with anyone and have a great time. Once you are on a home turf, now THAT’S where it gets interesting!
But — you’re a big boy, now! Good luck!
So does that mean not much hope for a stable relationship? I’m starting to get convinced.
I may be older but I haven’t gotten any wiser. I don’t think I can see her and remain analytical about the situation. Maybe it’s better to break it off now after all.
Even if she lived in the same place as you, I’d be very wary of getting back together with her now, based on what you’ve told us. The fact that your relationship would be long distance (which makes it much easier to focus on the positive, and ignore warning signs and potential problems) means I’d absolutely avoid getting back together with her. You’ll spare yourself time, money and anguish that could best be spent on pursuing a new relationship.
She’s lonely. I’d be wary. Like, lion-tamer wary.
Advice from a fellow who has never had anything resembling a romantic relationship (you got your grain of salt?): If it’s reasonably possible for you to meet this woman, and there’s a reasonable chance she’s not just messing with you in some way - why not go for it? As someone else mentioned, if you don’t do this you may be playing “what-if” games with yourself later. Go meet her, have a nice dinner - have fun, I’m told dates are supposed to be fun things. 
If the distance makes it impracticle to visit her unless you’re on a business trip or something, so this would require a substantial investment in effort - well, how much effort are you willing to put in for a fun night with a person you like? If I’m understanding you correctly, the problem was never that you didn’t like this person, but that she wasn’t interested in your romantically. But you like her, she wanted to be friends with you so probably likes you too - give it a shot. Just don’t expect to walk out of dinner with a wedding date.
Did I mention I know absolutely nothing about relationships? Thought I should reiterate that.
I’m one of those though not the only one. Long distance relationships (LDR) bring a unique set of challenges in communication but love is love. I sometimes despair that there will be a happily ever after given all the roadblocks thrown up in our personal story but then I realise it doesn’t matter, In the here and now our relationship is amazing, even if we are not in physical proximity. We have lived together and been in eachother’s space, that is important to us as we come from different cultural contexts. In this case with the OP having being in this relationship before there is a distinct advantage.
Physical distance sucks but not as much as emotional distance can suck even if you live together. You need to be creative, you need to make time for chit-chat, you need to open up emotionally as you cannot express things with physicality but LDRs can be as fulfiling as any other relationship, or they can suck like any other relationship. It is up to the players.