I always say "have a hard shell with a soft core" or something to that effect....
Be completely unshakeable on the outside but every now and then show your more sensitive side (but be careful not to overdo it). I have never been a badboy that women change, but I have heard that women like to get a badboy and then cause him to reveal his emotional side and change him into a better man....
who knows....
All I really know is that, like someone already said, you have to have some of the attractive jerk qualities but also some niceguy qualities (not AFC) as well if you want LTR's. It seems to me like most of the women who stick with true *******s for longer than 3 months are themselves very emotionally unstable and/or damaged goods, and you don't want either.
Being nice is NOT AFC. You can be as nice as you want, as long as it is always on your own terms. Niceguys who are AFCs are pushovers, feed women constant attention, are emotional tampons for them, buy them gifts, and also do other things which could also be seen as manipulative. The trick is, to be nice but have COMPLETE power and control of the situation. Treat the women like little girls (psychologically speaking they are looking for their new daddies

) Coc-ky/funny can be implemented easily into your niceguy character. Women WANT to be teased, and they want to find a masculine man. The other big problem with being completely nice and submissive all the time is that it is BORING, and, as we know, that just kills attraction. Be a man and have some dam-n dominance, some control, some unpredictability, like you should have.
I say all of this because many guys on this board just don't understand how to be a man but not be a complete jerk.