I had to read that thing plus the FAQ like twice to really grasp how it worked, and I'm still not 100% positive. I am nearly 100% positive that I like it, though. I was only vaguely familiar with the SC2 system back right after release so that may be why it's a foreign concept to me.
If nothing else, it's way shinier than an ELO number
Regarding the AD Caster stuff, Kog'Maw is in no way an AD Caster. He gets most of his damage from autoattacks, with his steroid on especially. He's less of an AD Caster than Corki even. Urgot I can agree with, GP I thought about but he's really just a bruiser that can build offensively. Kat is an AP Carry that has some AD scaling, building her as an AD Caster is basically fail mode but I'm sure you could win some games with it, just like with anything else.