I love dating women who smoke. The smoking area is the quietest place in the club and you can really use game to your advantage here. The other advantage is you get good isolation away from her social group (assuming she is the only smoker). The BIGGEST advantage to dating a smoker is they have an "oral fixation" if you know what I mean. i.e. They are very skillful at putting long things in their mouth
As for her sleeping with other guys, so what? It's the 21st century and some girls will sleep with lots of guys and decide who is the best one. Increase your social proof and sleep with other girls to increase attraction.