What on God's green flat earth are these requirements??
What about apt do you find too complex? I guess what are you defining as 'complex"?
I'm terms of package management you'll be hard pressed to find anything that requires less work that apt, yum, zypper or their various GUIs.
Debian is the most vanilla distro you can get and you are excluding it out of the gate because of apt. So it would be helpful for all of us to understand your complexity issues with apt (and zypper).
It was my first distro and I miss it a lot. Simplicity and stability are main selling points