1.Eee? where it is stated? Nope they can't have weapon even in warden case duncan says he lacks basic trening sure we they have many criminals but many of them is also simple beggars.
2.Remove alistair and the warden his party pretty much he would won without warden party as i said he was winning only the hero saved the day.
3.Absolute monarchy? nobility don't have all army in fact she would gain more allies than behlen considering how abusive place orlais for everyone not counting nobility. In fact even gaining some nobility support wouldn't be problem especially if she was ready burn some nobles one way or another in behlen style.
1.One, it in the lore. 2. The carta clearly can supply the weapon. 3. The warrior caste is also backing them. 4. You pick the traditional guy he and his ruler ship get taken down by a castless rebellion.
2. We already know he fails to do that. Which bring me back to my point that it's not just the Warden his plans fail. It's destine to fail.
3. Yes, nobles do have armies. Look up how monarchies work. Hell, just look at dao and you see that they do. And you're still not getting that noble can offer the same thing Celene can.
Sorry but ruler can't just do ANYTHING they want without considering the consequences and how much support they have.