his later ideas seemed to be worse-the whole "evolved, enlightened Humanity" thing, plus the wacky idea that Starfleet wasn't military.
Hm. Just felt like this one needed response. First, I don't think Roddenberry ever saw Starfleet as not being military. They are clearly burdened with the job of Federation defense/security when needed, they have ranks, the take their orders from a centralized fleet command. It's all pretty military. But what they aren't is an analog to most modern (say, U.S.) defense organizations. Defense is part of their role, but not necessarily their primary duty. That's summed up in the start of ever show: to explore strange new worlds, to see out new life and new civilizations.
So Starfleet is NASA combined with the Navy combined with the Merchant Marine... and maybe a few other things as well. But their primary job is not "blasting bad guys", though they'll do it if required.
As Roddenberry created Trek and Starfleet, it seems odd to say he's off base in defining its character? It's kinda like saying that Lucas was wrong in making Han Solo a smuggler, or something? It's his futuristic, aspirational vision so there's no real "right and wrong" to be had there.
I'm just sayin'