One thing I would like to see, in any future OS is, at an ending stage of the installation, a questionnaire similar to the customisation options that are in Windows 8, but dedicated to security options..
It should, in the first instance, offer as a choice, Microsoft's defaults, or, for the experienced user, no security implants whatsoever. With the latter, it could then have a questionnaire, with alternative choices of UAC,, Windows Defender...etc etc.
At a later stage, it could offer an unadorned IE, under the same criteria.
Whenever I install an OS, I spend quite a time removing security options, or adjusting them to my own preferences. Right or wrong, I have my own security arrangements and would prefer to continue with that free choice.