I do love Bargnani's potential, and I can't wait to see how good he gets, but there are a few things it seems like you are overlooking.
First....I think that you are the only person I have ever heard question Bosh for his shot selection before. Bosh is now considered one of the top 4 or 5 power forwards in the league by nearly everyone but you (and apparently the rest of Italy) ;)
Second...Mitchell runs a flow offense which require next to no set plays, this is why they fit on a napkin. The offense is effective, and since Mitchell came to Toronto it has been only their defense which has been questioned. Few truly successful coaches run a lot of plays. D'Antoni uses about 3 plays, Jackson uses maybe 2, Riley only uses about 4 or 5. A good offense tells players where to be on the floor and leaves the decision making up to them. You only run a lot of plays when your team is not good and you have to over-coach them. He gives the press answers like he does because he doesn't like to give them specifics....that is all.
You also mentioned that Bargnani should get more playing time because he is one of only three legit big men, but you also talked about his deficiencies playing in the paint, so he is obviously not really legit big man as of yet. Furthermore, if you ever want him to be one the Mitchell is the perfect man for him. Garnett himself credits Mitchell with mentoring him into the star player he is now.
It is tough to play him big minutes yet because he has not yet learned defensively how to handle either 4's or 3's and he is not strong enough to guard 5's. Once in a while he puts out a good game defensively, but often he has been a liability.
You also mentioned that Bosh does not pass to him but there is good reason for that. When Bosh has the ball and is looking to kick where is Bargnani standing? He is setting up on the weak side 85% of the time. This is designed (by Mitchell) to try and get Bargnani open looks on the swing. In other words, the person usually to blame if he is not getting shots off of Bosh posting up is not Bosh or Ford but usually Parker, Kapono, Moon, or Delfino.
Anyways...I just am having trouble figuring out what it is you don't like about Bosh and Ford because the rest of the world loves their games AND thinks they are a good fit for Bargnani as teammates.
As a Canadian I sure like Steve Nash, but it never occurred to me to blame his teammates when he struggled early in his career.
Anyways, I do understand your desire for him to play well, cause I have felt it for other players, and I hope as much as you that he becomes the star he has the potential to be. I just wish you wouldn't blame people who have widespread reputations as good teammates and unselfish players.
Whew...I never meant to write an essay ;)