Should I withdraw my other PhD applications when I have a secured funding and a supervisor but I am waiting for the faculty decision? I'm applying for PhD studies to a university in Netherlands, the procedure entails that you should contact a professor and obtain a letter of acceptance. I have already secured funding and now found a supervisor and obtained acceptance.  I now have to obtain admission from the faculty.(Which will take about two months) I have sent out other applications and I was in the middle of sending more PhD applications. I want to know: 


What are the odds that I will be denied admission even after securing funds and getting acceptance from a professor working in the faculty?
Should I stop sending out applications and withdraw my other applications now or wait until I am granted admission by faculty? (I have read on this site that wasting other people's time in academia by going to interviews or applying for a position you know you're not going to take is considered unethical).
No!

Until you receive an official offer of admission, you have not been accepted to the PhD program. Do not withdraw your other applications until you have actually been accepted somewhere.

(In fact, I would not recomend withdrawing your applications at all, but rather, if possible, waiting until you have all your official admissions offers and then deciding which one to accept.)