#1 NO MULTIPLAYERIts entirely easy to see that, while ME3's multiplayer was ok, It took up a little too much of their time. I would rather bioware focus all their attention on the singleplayer. Besides, DA is meant to be a singleplayer only game that relies on tactics and companions to survive, so a multiplayer would just complicate things. Now, I'm not opposed to a multiplayer (preferably coop missions and not the enless horde mode of ME3) but it would have to be made after the initial release so as not to mess up the game's singleplayer. Sorry OP.
#2 Better level design.I'd rather not see the same middle eastern style town over and over again (though it should be featured). Personally, I want to see more of the world and Bioware has a clear and great opportunity to give it to us. Dungeons should also be unique. There were some reused maps in DA:O, but not many. However, in DA2, almost every dungeon had at least 3 or 4 copies of it where you would spawn in a different location and there would be a different path to a different location. Sounds good on paper, but in practice, it looked bad, was boring, annoying and completely imersion breaking. Don't do it. Take the time to make unique dungeons and environments that we can all explore and enjoy and the quality of DA3 will go up quite a bit.
#3 Tougher enemies, but less of them.In DA2 it got to a point where the enemies with small health bars were just an annoyance, even on high difficulty. DA:O enemies were perfected, where they were harder to kill and had much more support and abilities to boot, not just the mindless zerg of the seemingly endless bandits or thugs. Special enemies should also be a little tougher as well. This doesn't mean you should remove the slightly faster style of the combat in DA2, It means you should make enemies tougher, not more numerous. It should also be noted that tactics don't play as large of a role when the squad is simply being zerged. All the player has to worry about is DPS, and that is not the tactical combat that was so well implemented in DA:O
#4 Don't market to the mainstream audience.This was a massive mistake made in ME3. Trying to market a Third-Person Story-Driven game to the masses of Call of Duty and Battlefield Players just doesn't work. So Please Bioware/EA,
DO NOT MARKET TO MAINSTREAM AUDIENCES. It messes up the game for the rest of us. More importantly, It doesnt work. The mainstream audience is more concerned with games like Call of Duty, Battlefield, Counter-Strike or Team Fortress. They don't really have a huge amount of interest in RPGs. So instead of marketing and tailoring a game to an audience that doesn't have a whole lot of interest in your game to begin with, why not market to the RPG fanbase, aka Your entire original fanbase. ME3 proved that saying "Forget You!" to your original fans and trying to attract a group that is already established in a different genre just does not work and is a bad idea. Do not make this mistake with DA3.
#5 The return of the origin system and silent dialogue.
One of the awesome things in DA:O was the fact that you could create a character with a race and background of your choice, and then play through the game as that character that YOU made, not the character the game makes you play. Now, I did like hawke, and i liked the character, but there were only 3 ways to roleplay him/her: Really nice person, Smartass, or complete douche. It got so tiring and repetetive to play DA2 on following playthroughs because the same events happened, hawkes says the same things, and the story always turns out the same. Not being able to choose hawke's race didn't help either. So I, personally, think that it would be better to return to the original system in DA2, where the hero never said anything (didn't have audio for dialogue) and had more options to choose from than just Good/Smartass/Evil. I also would like to see the origin system return (If the player isn't playing as the warden or hawke) since it added alot more to new characters and immersion. It also added alot to the way certain encounters or conversations would play out, and generally made the game better. Consider it.
So there it is. My 5 things that i think Bioware should do in DA3. I know they will likely not read this and if they do, it will not be the only opinion they consider, but there it is nonetheless. Thanks Bioware!