Hey! I think your thoughts on Hide make sense, I just feel like, if Hide is just an ordinary clever human, then why don't we know anything about his past? Compared to everyone, we know very little about him. I just find him sketchy. Doesn't have to mean he's from the Garden haha, and of course he wants to help Kaneki. I don't know, in chapter one, especially in the redraw, he acts very suspiciously. Especially after seeing Rize. Of course that's just my opinion xD.
We don’t know anything about Yoriko’s past or parents either. It might just be that they’re not relevant to the plot, and since Hide functions more as an extension of Kaneki’s character - the manifestation of his humanity - rather than as a proactive character in his own right (although he has been edging more towards this recently), they would kind of be unnecessary elements. We only meet Takizawa’s parents so that he can eat them later on, after all.
I’m guessing the “Ghoul closest to you” was just a joke on Hide’s part. If he genuinely was hinting that he’s actually a Ghoul, then why would he risk his cover so recklessly? I think it was just meant to foreshadow the reverse scenario in Kaneki becoming a Ghoul, or else Hide’s future as a Half-Ghoul. I don’t really see the suspicious behaviour myself. I’ve heard people say he was trying to either encourage Kaneki to go with Rize or stop him from going with her, in both cases because he knows she’s a Ghoul. I think the former is disproved since Hide starts off by discouraging him, and the latter is disproved by Hide not being adamant on the subject and letting Kaneki do what he wants. He jokes around and then gives serious, friendly advice afterwards, just as Hide normally would.
In any case, it’s the original first chapter and not the redraw that is the true canon. We should definitely pay attention to hints in the redraw, but also keep in mind that it’s not the true version of events.