Can i mix chantilly and cream cheese to stabilize a cupcake frosting

Absolutely! Whip up the cream cheese first, add about a quarter of the chantilly and mix to lighten the cream cheese then fold in the rest of the chantilly, as you would with a meringue.

I think you certainly can. I make one with mascarpone all the time and don't see why cream cheese wouldn't work:
https://food52.com/recipes/24457-mascarpone-whipped-frosting

If by "chantilly" you mean heavy whipping cream, then the answer appears to be, "Yes1' I have not tried it, but here is a link that you may find helpful: http://www.themerchantbaker.com/whipped-cream-cream-cheese-frosting/ ;o)