If I need to rebuild attraction which is fading and her IL is fading, how do I do this if I see her out and about on campus?
Why do you need to rebuild attraction? Have you considered adopting a non-caring attitude and letting her see your less needy side? Why are you concerned with rebuilding her interest in you?
Asking her out just gets me flakey non-committal answers. Is really showing disdain and ignoring her going to prop up her low IL?
Ignoring her is ignoring her. Why not assume her flakey non-committal answers and plan around them? Why not plan before hand that she will give you these attitudes and go about setting up a "game plan" to overcome these obstacles? Or any derivation that works for you.
Maybe if you set your goal (getting a date with this girl),
then plan every step you need to take to attain it (attracting her, demonstrate high value, show your manliness and and decisiveness)
then if you plan all the possible obstacles you can think of (she outright says no, she is busy, she cant give you a decisive answer, etc)
and then you plan to overcome those obstacles (laugh it off and continue conversation to try again - keep things mildly sexual (tension), tell her no problem and dont try to plan a future date - instead try to just meet up with her again in a completely casual place to try again, or if she cant decide then maybe she is waiting for a man to lead her, if you dont then who will?). If you do this you'll probably succeed; spend a few hours on it, but remain detached from the outcome. if she fails as a date then she isnt worth it and you can fish from the rest of the sea.
I feel like ignoring her is going to take a long time to work, is she really going to notice I'm not pursuing her or trying to arrange a time to meet up with her anymore when I've been so resolute in chasing her for a date everytime i see her?
If you aren't excited about engaging in that behavior then dont do it and instead adopt an attitude and countenance of fun, pleasure, sexual excitement and manliness that she responds to, versus a obliging task of having to ignore her. If you enjoy being around her, show her, if you want to date her, do it, dont ask, lead her, take her on an instant date for coffee at starbucks or something similar and engage in a stimulating conversation. Be energetic and passionate. There is little need to worry about what you need to do if its stressing you out. Instead focus on enjoying yourself or dating her could seem seem like a chore instead or the fun that I am assuming you want to enjoy?