Well, I don't think these characters have much of a social life, and the fact that Flack works with the YMCA kids was a great touch, and says a lot about the character.
As for the friendship with other characters, it's not all about what happens outside of work, it also includes the interactions when they're on the job as well. The friendship between Flack and Stella is a great example of this. We know they have a great rapport going on not because they hang out after shift, but because of the way they talk to each other and how they get along.
The friendship with Danny is definitely expanded in fanfiction, but when asked about it in interviews, both Eddie and Carmine have spoken about the friendship in a positive way. So it's definitely there. I don't think Danny being close to Hawkes (and knowing a lot about him) lessens his friendship with Flack in any way, but I would go so far as to say the relationships are probably quite different.
I don't assume that the characters aren't close to their families because they never specifically mention spending time with them outside of work, so the same is true for friendships as well, at least as far as I'm concerned. The whole team could go to Sullivan's (or whichever bar they go to) for a beer every week for all we know, even if they never show it.
As for the friendship with other characters, it's not all about what happens outside of work, it also includes the interactions when they're on the job as well. The friendship between Flack and Stella is a great example of this. We know they have a great rapport going on not because they hang out after shift, but because of the way they talk to each other and how they get along.
The friendship with Danny is definitely expanded in fanfiction, but when asked about it in interviews, both Eddie and Carmine have spoken about the friendship in a positive way. So it's definitely there. I don't think Danny being close to Hawkes (and knowing a lot about him) lessens his friendship with Flack in any way, but I would go so far as to say the relationships are probably quite different.
I don't assume that the characters aren't close to their families because they never specifically mention spending time with them outside of work, so the same is true for friendships as well, at least as far as I'm concerned. The whole team could go to Sullivan's (or whichever bar they go to) for a beer every week for all we know, even if they never show it.