Really? I thought, if anything, Parasite confirmed that Sylar wasn't eating brains, but that the more realistic(well, the more acceptable) theory was correct. That he was looking at the differences in the brains and figuring out how they worked. Most people choose to take the line "let's see how that works" literally, mainly because the idea of him chowing down on brains is lame.
Btw, I agree with your criticisms about the show. I love it. I really, really love it, but watching the first episode again I couldn't believe how stupid Mohinder's speech to his students was. It was a cute little coda when he squished the cockroach(arguably the image of God!) later on, though.
I think a lot of the actors do well, particularly the younger, less experienced ones. Hayden Penettiere as Claire is great, as well Masi Oka as Hiro. I find the older actors less convincing. Granny Petrelli in particular really isn't played that well. Like you say, the show's laid back charm is what saves it from its minor faults.