TBH I'd rather them just kill every protagonist off at the end of each game now instead of doing what they're doing.
If you can't control a previous protagonist that you created and instead have them around uttering gibberish whilst donning crap armour then they are no longer your character.
Either keep them in the background or kill them off entirely.
Instead of each hero mysteriously vanishing Bioware style, they should have it where they are simply "mysteriously killed" and found dead at the end of each game (providing they don't die in the actual ending after the main boss). If they survive their ordeal then after you watch the cutscenes, you get text coming up telling you about your decisions and your companions whilst triumphant music plays and then after this, the music abruptly halts, everything turns silent and a black screen comes on where white writing slowly appears on it saying "Sadly you didn't live long after your victory and were found mysteriously dead in a back alley of Denerim. The people would never forget your sacrifice." and this is the fate for every DA protagonist from now on.
I'd prefer that treatment to what they've done right now.
If Hawke's role in Inquisition was simply to offer you plain advice and then join you in the final battle, then that could have worked. Having them be around getting emotional about Anders (even if they killed him), cracking jokes and becoming heavily involved in their own plot? Not so much.
So I agree they should have given us control at one point but forget dialogue wheels, I'm talking about where we should have ended up with a one hour section just controlling Hawke giving a better closure.
Thing is, I don't think Hawke would have appeared in DA3 had the expansion "Exalted March" for DA2 happened (which would have been the closure) and DA3 would have been entirely different. Because it didn't happen, half of its ideas ended up in Inquisition and we got Hawke as an NPC instead.
If previous protagonists characters appear in future, give them insignificant things to say around the new player character and then let us control them when they go off and do what they do in their own chapter or whatever.
The only way I can see two-player dialogue wheels working is if they did it in the Divinity Original Sin style I suppose but I think Bioware would see it as a bad mechanic to have suddenly introduced this mid-way into the game when you meet Hawke when he/she is only in the game for a little while and admittedly I feel it would be disjointed to suddenly throw new players into forced two-way convo.