What Platform are you playing the game on? If PC, can you provide a DxDiag? PC. http://hastebin.com/raw/haneqageba
What areas have you been in when the problem was reported? All areas. In 58 hours of play, I've had non environment based party banter fire twice.
Have you already entered the Hinterlands? Yes.
Are you mostly spending time on Critical Path plots? I've completed up through the Winter Palace plot and have met up with Hawke's Warden friend in Here Lies the Abyss.
What is the the Race/Class/Gender combination of your Inquisitor? Human/Female/Mage
What followers are you using at the time? All of them. I constantly rotate the party and have had tons of combinations. My first instance of non environment party banter was between Sera and Blackwall and my second was between Cole and Dorian.
How would you describe your play-style? No stone left unturned. I seek and explore every nook and cranny. I also am constantly fast traveling, going through menus, and shooting/harvesting any animal that gets in my way.
How are you moving around in areas? For example, are you using the mount? I use a mount less than 1% of the time. It would interfere with my stone and herb collecting.
Are you playing a mage and using Blink to move around areas? I've never used Blink.
Are you engaging in regular combat? (Are you in combat every 30 seconds?) No.
Are you playing in heavy-combat zones where non-player factions are fighting each other? Sometimes yes and sometimes no. My Hinterlands area is really calm right now, no more mercenary camp, templar camp, or mage camp, but I still have no party banter while walking around.
How many hours have you spent in your current playthrough? (the one you are experiencing the banter issues in) 58 hours
Where do you expect banter to be firing? While walking along open and empty stretches of the Hinterlands, the Storm Coast, the Western Approach, etc., with no enemies in sight.
I, like a lot of other people, can also get party banter to fire if I set my party in a safe corner and put down the controller for 10 minutes. That's not the issue. The issue is that you have too many constraints that are pausing or resetting the banter timer. I play for 58 hours with only two instances of banter firing, but I put the controller down in a safe area and the banter fires for the third time ever within 10 minutes. Something ain't right, guys. You need to adjust how banter fires to take into account how people actually play your game, not how you'd like or expect for people to play your game.