Yes, he is credited in the "special thanks" section as Fluffy the Dancing Ogre.
As for the mounts, like others said, I won't use mounts on my first playthrough (unless they are required to go to specific locations). I would use them should run a solo playthrough, or after I know what/which spots trigger party banter, or when revisiting certain areas.
Or maybe party banter generally doesn't occur in the open countryside and is limited to settlements and areas you can't enter while mounted. You know, sort of like how it worked in DAO?
In the Digiexpo/PAX 2013 demo, they said companions will point out locations of interest. For example, Varric and Vivienne talked a bit when they spotted that valley in the Western Approach which was filled with poisonous gas. So I guess it does occur while you're exploring the countryside.