I'm in the pro-flirting camp. I make a conscious effort to talk to people, especially new women, and try to get an interesting conversation going. In my case, my IC thinks I'm in such a panic over the S in part because I'm convinced that I can't ever find someone else as good as my W. I know you have the same issue because you said this exact thing here. I can already attest that I'm getting better, more confident at it and that it has given me some relief over my sitch, or at least something else to think about on the romantic front.
As for "dating", it depends what is meant by that. If it's going for coffee or dinner with new people, I've absolutely no problem with that. If it's about have a one-night-stand, I still think it's defensible (will I be moderated or banned for this??). Oh and I'll say it: I even think LBS in situation like ours (WAS is gone, moved on with someone else, D proceedings, etc.), it's ok to date more regularly. I'd make sure the other person knows I'm separated though and that it wasn't my choice. As you know, my view of marriage is less constraining than that of many around here.
I seem to be fairly alone around here in thinking that it's not unfair to the other person, even if you're still "available" to your WAS. Everyone has a history and new relationships aren't life contracts. We feel each other out, get to know each other, seek compatibility, etc. It fails in a large majority of the cases, by the way. I wouldn't mind dating someone who's not completely over their ex, as long as I know about it.
Anyway, I'll probably be told that I have low morals. Also, I lack experience and I keenly observe that vets are strongly against it, and so is MWD. Maybe experience will make me fall in their camp.
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.