"You mean one could inflect "theou" in genitive but not inflect "stylos", and still refer stylos to theos? (I am using stylos and not the other noun and adjective because I am fairly sure of how to inflect stylos)."
I think so, yes. If stylos were an adjective, it would be different. I just don't see it being said that way. More likely one would say a clause beginning with tou. But then again, my Greek cousins tell me I speak Greek like a Spanish cow (same thing my French friends say about my French)! :)
Well, by that logic, "zontos" is a participle working as a an adjective, and it is not inflected. You are correct, that "tou" would be necessary as well. I think Blogger's reading is to Greek what Japanese appliance instructions are to English.