Agreed. When he started explaining the Ultron thing me and my sister looked at each other at all the stuff he was getting wrong about it (because, obviously, he wasn't there when it happened and - per usual - is making his own assumptions that feed/make him feel like he's justified in what he's saying).
Simmons was running all kinds of tests on his blood last season trying to find *any* traces of the GH325. Something rewriting his DNA I would think she would notice. I think it's out of his system - and with the hypergraphia issue gone - I think he's normal and human and that's the way it should stay. The thing that I've always liked about Coulson is that he's the every-man. He's the completely normal guy dealing with this now weird world. Making him any type of enhanced (even the things you listed) kind of (IMO) diminishes what I like so much about him. Just my take.
Onto the episode, loved it. Didn't care for Coulson agreeing to have a 'council' for oversight - at least - not that council as it stands. It's too far lopsided in the *other* direction from Coulson (with their Xenophobia) - May's the only one not at that level, but even she has become disenfranchised with some of Coulson's methods. There needs to be more balance on an oversight council and (IMO) that one just doesn't have it.
With Jiaying, I started to wonder if she might find a way to kill Gonzales (or if Gonzales was going to pull some stupid stunt and force her too). I definitely don't agree with what she did - she was definitely wrong to handle it that way and start an all out war (though I can understand her why of not wanting her people to be categorized and monitored (cause lets face, history has shown that tends to go very badly)). But I can't say I'm mourning over the loss of Gonzales. His ideals have been pissing me off since he was introduced, so I'm not really that sad to see him go.