Auto-billing can be turned off on your account page.
It isn't normal for McAfee to break anything - goodness knows I've uninstalled/reinstalled it a thousand times in an effort to reproduce what people are asking about.
Every security software suite is different obviously and some find what the other missed, but the same goes in reverse too.
Never rely on antivirus/firewall alone, always have some anti-spyware applications handy and updated as well.
Some are listed here: https://community.mcafee.com/docs/DOC-2168
Also always keep Windows totally up to date and surf wisely.
Anyway, good luck to you.