This all somewhat reminds me of Dragon's Dogma, with the mapping of skills. This needing to be done prior to setting out on a dungeon crawl or quest. Whatever you map, for you and your pawn, is what you get to play with, till you get back to an Inn or another resting spot. And it varies with vocation. For Mage/Sorcerer, you get 6 total mapped spells (out of roughly 22-25 spells that you can "buy"). For Strider/Ranger, you can map three dagger talents, and three bow talents. For Fighter, three sword talents, and three shield talents. Warrior, only three skills can be mapped. Basically, only three to six spells/talents can be used at any given time, and to change those, you must find a purveyor at a resting spot, to switch that up.
Now, this could end up working just fine in an MP scenario. Like Dragon's Dogma, it is action/real time fighting, in MP. (DD did allow you to go to your item/equipment menu during combat, but no tactical/pause-n-play situation.) But, for Dragon Age SP, I will sorely miss being able to use the slot list 15-20+ on the bottom of the screen, or the Radial menu on the console (play on both Xbox and PC). I am a huge DD fan, but I play these game differently, and truly appreciate their differences.
Having said that, I have no doubt that I will be able to adjust (heh...maybe I can call all those hours in DD "training" for DA:I

). Whether or not MP had an influence on these changes, who knows. But, it is, what it is.