I have a lot of admiration for Tina's tenacity w/ regard to the Michelle situation, but I'm struggling to warm to her so far, too. A lot of that could be mitigated depending on how Jen Finnigan plays the character, and I'm assuming the show will give us more opportunities to see ALL of these people interact. How she plays off of Ty, and Hooten, and Michelle would help. (I guess actually, this gets to an aspect I should have mentioned above - there are a lot fewer extended dialogue scenes in this book than in most novels, and maybe that speaks to SG's relative inexperience as a fiction author, but it does feel at times like he does a lot of telling and not a lot of showing w/ regard to character. Hooten I can give a pass for a while because he's sort of a figurehead anyway; you can open up a character like that later in the game, and with Molina I know for the time being he'll be solid.
You're right, Ving is NOT as heavy as the character is depicted, though he is pretty husky. He could definitely be an ex-NFL player. I don't really see that being too much of an issue in the show though; they can always write around that by showing him just being very energetic and barreling around the trauma unit. Slow down, doc, you're knocking shit over. ;)
It does seem like legally, Ty would have been warned against contacting Quinn's mom, but... now that I think about it, the legal aspect of that case hasn't been addressed in nearly as much detail as the chef in Michelle/Tina's case. I wonder if SG will make that reveal in a subsequent chapter. At any rate, yeah it's a bit reckless but given Ty's personality type and how seriously he takes a) this debilitating self-doubt he has now and b) how personally committed he is to serving the patients because of his family history, it's not an enormous leap IMO to see him throwing caution to the wind over this mistake.