My favorite lines that kill the what if he's... is "
CR~Now when we hang out let's go somewhere bright and where there's a lot people. I don't want to be kidnapped.
HB~Well, even though it's me kidnapping you?
CR~Well, I have to be home at some point or my Ferrari turns back into a pumpkin =P.
Another line I use is
CR~I am immune to chloroform so don't even try it =P
HB~Well, I guess i'll just have to roofie your drink

Oh darn did I say that out loud?
CR~ Say what out loud
Find out what works for you, I just use these because it get's them laughing and actually playing on my jokes.
Never say that she can bring her friend this will most likely destroy your game
Set the date or "Hang out" for early afternoon with a few hours til dark. What this does is it creates a feeling of safety and easiness to the date. She will think you are not looking to F-close, that she can come up with excuses to leave, and that there won't be the "My house or yours" conversation.
What this also does is open up the time frame that you have, lets you bounce around to multiple locations, hit many different topics, and get her feeling that she has known you for a while and hit it off. So what you are doing is adding some more time to the clock to get more points scored.