I'm glad that there are still some people who can express their opinions and complaints in a civilized manner. However our opinions greatly differ, let me add notes to the original post.
1) You cant cancel quests and destroy questitems
-Which is actually a necessity in MMOs, but wouldn't make much sense in a story oriented RPG. -You took the quest, it happened in the story. You can't simply cancel it. You can pretend you've never got it, and ignore it. As for quest items, to be honest, I've never even looked through them in the inventory. Maybe once.
2) Not an option to position you men correctly. You cant for instance tell your archer and healer to stay put and then let the rest of the group run freely. Either all freeze or none. IMO thats a design flaw.
-In this, I agree, it would be nice to have an addition in a later patch that allows us to tell different companions whether they shall hold position or not. On the contrary, in easy or normal you don't really need it, on nightmare you'll pause every time anyways (unless you use storm of the century, hee heee). And archers and runners only ran a few times in battles when the line of sight was broken, that two seconds to set them straight never really bothered me. Not like Mass Effect (I know they are a whole different style, no need for reminders, still, same game developer company), here you can control all the teammates. So giving an order every now and then is not that tragic.
3) You cant see who is affected of your spell and how long the duration is. In battle everything ends up being a lot of guessing and assumptions. In a game where strategy and teamwork in your group plays such a big role I consider this a design flaw also.
-I think it's easy to keep in mind. Major debuffs like vulnerability hex has an outstanding graphical aura, so you can see if it's up or not. But maybe it's just me, to be honest I only used a few debuffs, as I followed the policy "Dead enemies don't hit back" even on nightmare. But I never found a real need to debuff cannon fodder anyways, and for the one elite/boss target, I could easily keep in mind what countermeasures I used. It's not that hard, really. Of course if you debuff every single mob on the screen, that can be overwhelming.
4) The targeting system is bugged.. at least on the PS3. You dont have the option to log onto a target properly and everytime a mob runs in the way the targets changes. Even if you pause, choose a mob and then release pause and instantly click a hotbutton the spell may hit a totally different mob than intended. In a game where every choice counts in the heat of battle, I consider this a design flaw, and pretty close to being gamebreaking.
On PC it is fine. Cannot comment the PS3 version.
5) Poor quest design. I actually like that you have to think a little yourself and dont just get pointed to the next objective. But when I get a quest in Denerim saying that I should find some guys sextant and I get no information about either the guy or the item I really feel I get TOO little information. I dont know where the guy lived, where he went or anything else. I am just told to find an item but I dont get a SINGLE clue about where to start. I LOVE riddles and I love games where you need to do a bit of thinking yourself, but PLEASE give me a small hint on where to start at least. IMO that is poor questdesign.
- In my humble opinion this paragraph is meant for effect and doesn't have a valid point when it comes to the game's quest desing. On this particular quest you're right, but anyways, when I didn't find it exploring the city, it was evident to me that it will be in one of the locked down areas. And this is one quest. The others - I found them fine. So you can't base an opinion of broken quest design on one silly side quest. In case you have twelve or more examples that's a whole another case. In my opinion, DAO's quest representation is one the best I've ever seen.
In fact -despite all the minor flaws, and bugged ending texts and dialogs- Dragon Age is THAT great. It hat to be said.

May the Maker be with you, my friend, shall he guide you to a working targeting system.