Not sure if I can mix that out, meaning SS 2.0 Suitelet loading a SS 1.0 Client Script...

I believe this is possible, you are only not allowed to mix SS 2.0 and SS 1.0 in the same JS file.

I'm not missing it, it does not work with SS 2.0 you can only use Suitelets with attached Client Script code with SS 1.0...