You've all made great points about the characters, and I pretty much agree with all of them.
I would like to see someone other than Flack tell Mac how it is. I felt with those particular scenes in Season 3 that Mac almost dimissed Flack's (very good) opinion regarding how he should handling things, for whatever reason. I got the feeling it was because he was younger, perhaps a little hot headed (although as we've seen many times that he is out done there by Mac and Danny), and maybe a little be inferior intellectually - although that is purely my opinion and as we've seen this season Flack has been Mac's shoulder to lean on.
Danny never really annoys or irritates me but sometimes I do want to give him a good talking too. This IMO is more the writers fault than the actors, apart from Lindsey - don't get me started
- and rescuing Hawkes and Adam, physically. I don't think i've ever seen Danny really step up and be THERE for a member of the team emotionally. Fair enough, at least it is continuity
but there have been times, especially in Season 3 where I felt perhaps Danny should have been a better friend to Flack specifically, after all the guy has been there for him. This lack of support for me made Danny seem a bit flaky and I don't believe the character is meant to come across like that at all, CG never plays him like that - he is shown to be incredibly loyal about the people he cares about. It's probably my biggest gripe.
Even though Adam is not shown nearly enough. I think the writers and actor have flashed out an incredbly good character, i feel i know more about Adam than i do about Lindsey, which when you think about it is pretty sad, since Adam is just a recurring character!!
Regarding Flack, I do feel he is a bit Super!Flack. He is all things to all men. He plays it by the book (although he does bend the rules for the people he cares about most. Hee!), he is a rock for most of the team, Mac, Stella (in All Access), Danny - to many to name - he hands out advice, he is the humour and is often used to represent us the audience. He can deal with hardend thugs, fruitloop and wackadoos, never falls prey to a person's sob stories although i agree with the poster on here that pointed out he often jumps on evidence without the benefit of context, but then that is his job and in fairness to Flack, Mac couldn't prove that it wasn't the suspect he had a gut feeling it wasn't and set about proving that. I'm going to digress, how many times has Mac jumped on Danny for that!? regarding Flack's snark, I personally like it, i see it as the characters way of protecting himself and his emotions, we've never really seen Flack totally lose it, worried, pissed off, angry, disgusted, happy even, but never a complete breakdown (and i'm not sure we ever would or would want to because that just isn't Flack) and IMO his snark is to make sure he doesn't.
I feel like i have rambled. apologies.
Edited: As good grammar and punctuation is the backbone of society, according to my mother.