I definitely think Dick isn't pretentious and not overly picky about his drink, but I imagine life in the mansion has rubbed off on him a little bit and he has *some* standards, too. I think he'd drink a "peasant's beer" without complaint and be happy with it, but if he has a choice he'd go for something a little higher end, but not top shelf.
I think Bruce would drink socially as part of his "playboy" disguise, but otherwise yeah, he's teetotal. I suspect Tim largely doesn't like the taste of alcohol, nor the sensation of being tipsy/drunk. Cass wouldn't drink, I don't think.
I can see Babs enjoying a glass of wine, and maybe letting herself get a little drunk with Dinah as her drinking buddy/bad influence.
I don't think the title sells well enough to totally justify a second solo, but a "Nightwing & the Titans" type of book, where Dick's *a* main character with his name on the cover but is still part of a wider roster, is actually a strong marketing strategy.