Yes.
CG-Lion Car Paint Presets Pack 1.0 supports rendering in Cycles at both CPU and GPU rendering modes.

No.
The CG-Lion Architectural Glazing shader is an optimized customizable compound shader designed to render fast and efficient architectural glass surfaces by using transparent shadows instead of a demanding caustics calculation, and also skipping the internal reflection calculation.
It is generally suitable for thin surfaces of even thickness like windows, facade glazing, glass walls, glass tables, cabinet doors, car windshields and so on,
And less suitable for irregular full glass volumes like glass statues as it won't produce the lensing lighting effects caused by such surfaces (caustics)

No.
CG-Lion Car Paint Presets Pack 1.0 works only with Cycles render engine.