Okay so your definitely in the friendship zone. & now you've just DHV'd that your not always available because you lead an interesting life. So neediness & comfort have dropped slightly. and you've gained a fraction of attraction.
Remember though, don't always ignore her for the sake of ignoring her. If you take it too far she'll become disinterested. Try and actually be busy.
As for being flirty, you need to build it into the frame, one step at a time.
I find msn helps this transition, because you can have several separate conversations into a short amount of time.
I consider flirting essentially "Bait hook reel release" and shit tests.
This is how a Bait-Hook-Reel-Release would go if a girl turned up at my door:
Me: Come in

(Lots of energy)
Her: haha *walks in*
Me: Give me a hug (Compliance test - bait)
Her: *hugs me* (Complies - hook)
Me: You know in france they kiss instead of hug

*points to cheek* (Reel)
Her: She complies and kisses my cheek
Me: Ew, you just slobbered all over my face!

(release)
If at any point she doesn't comply, simply release. releasing is simply a neg.
Bare in mind before you start using this you already have to have attraction, and comfort to a certain point. You'll know when your there, because it won't seem awkward.
Continue your DHV's (you will need a lot to balance the comfort), So power on with that. Then when the attractions clearly there, throw these in, add kino and your good.
Remember, attraction is crucial, so watch out for those shit tests. You'll probably get a lot.
Wolfus