If you constantly have to talk about how smart/cool/deep you are to your date, then you are none of those things. As your 9th grade English teacher at Deerfield should have taught you: show, don't tell.
PDA should have some limits. Yes, you're out and about on an amazing date in a cool city with a person with whom you've got great chemistry. A stolen kiss up against an alley wall is understandable, even acceptable. But not everyone wants to be an unwitting witness to your extended game of tonsil hockey, complete with audible spit swapping (like the octogenarian at the pub who's just trying to enjoy his whiskey in peace). Not every venue is appropriate to basically dry hump in (e.g. churches, war memorials, etc). We're happy for you and the passion you have, but to put it simply: get a room.
Be fun. Don't dominate the limited time you have on early dates with personal sob stories. Yes, you can have moments of real honesty and vulnerability, but make sure you balance those out with some levity and laughter. Debbie Downers get dumped.
First-date sex is fine. You both want it? Go for it. You want to do it with multiple people around the same time and they're down? Woohoo! However, if you happen to be dating multiple people who are looking for a long-term, monogamous commitment, it is responsible of you to make clear to them that you are not going to be "exclusive," at least not at this early juncture. Giving a person the false impression that you only have eyes (and other body parts) for them, when that's not the case, even if it's just a lie of omission, is not cool.
Don't kiss and tell. It's nobody else's business. You're not honoring your burgeoning love, you're just stroking your own ego and, if you're on "The Bachelor/ette," engaging in psychological warfare.