I think what GR missed out on was that it wasn't that viewers who bought into the optimistic Trek future wanted perfect humans, they wanted to relate to "better" humans who fought and successfully overcame their lesser natures on the show, not somewhere in the past or off-screen. Kirk wasn't perfect - he didn't always have confidence he was doing the right thing or have the answer right off, but he would find it.
Having Tasha have to fight to overcome her upbringing (or lack thereof) sometimes would have been better.
Yeah. If nothing else, it would give the rest of the crew someone permanent to talk down to, instead of hiring expensive guest stars.
Maybe Roddenberry did turn them all into weenies, but there was still interpersonal conflict at least as late as his TMP novelization. Also several references to Kirk's boner.