I can't make your choices for you, if you want to continue dating them that's your choice. However you might want to seek getting intact IRL. If you do make sure that you are in a public space or you bring a friend.
It depends. Some people take online dating more seriously than others. I've had a few good relationships with people I've met online ( it wasn't imgflip though) so it's possible. But it's also possible they could take it less seriously than you might be. The best thing to do is to talk it over to check that you both are on the same page.