Once I set the all the companions behavior to follow or guard themselves, they stopped doing dumb things in combat. It really changed the AI behavior for me. And I also like to limit the amount abilities my mages and archers use, I like to give them an offensive skill or two, and then give preferred status to things like stealth, evade and fade step. They seem to stay alive and out of my way more, with that setup for me. So If I need a revive, I have npc's who are still alive that can stealth in revive me or cast revive. With my melee guys, I've tried a variety of setups with the abilities, and honestly I've gotten to where it doesn't matter cause most battles are faceroll as you guys call it. I tend to feel fewer allowable skill actions make the AI behave more sensibly.
I did kill the crestwood dragon with Sera in the group, and she got all excited like a little school girl after, and then I noticed a codex entry popped up for Sera, so I'm kinda curious what that meant. I need to make a visit to her room have a chat. To see if any new dialog options are available.
I haven't had the banter issue others have had, its truly a fun part of the game. The NPC's all have very strong personalities. I've had some great ones with my ****** squad (Dorian, Vivienne, Sera) They're so catty. Solas and Cole are trippy. Cassandra trying to be apologetic to Sera for being a noble, trying her best to be sincere, but sounds like an elitist. Seriously great work on this part of the game if you ask me.