Both of you are talking out of your respective arses. (Which admittedly is better than talking out of each other's arse. That's proper weird. Don't do that.)
Of course Ferguson is unlikely to turn out to be a good manager, but not because of what he was like as a player or whether he's allowed to shout bollocks from the bench, that's ridiculous. The reason he's unlikely to be a good manager is simply that very few people are.
But unfortunately there is absolutely no reliable indicator of who has what it takes, if there was, do you think Roy Keane would've been given so many chances? Or one, for that matter. Lobanovskiy was a flamboyant and uncontrollable player with a terrible attitude. He ended up becoming one of the best managers of his generation, and one of the strictest disciplinarians too, even going as far as pioneering computer modelling of football. Who would've thought it? Nobody.
Then you have Garry Monk who had done virtually no coaching in his life, he went straight from being a player to being a Premier League manager and he doesn't seem to be fazed by it much. We could also list lots of good coaches who proved to be hapless managers. (Terry Connor, anyone?) So coaching experience isn't a good indicator either.
Maybe there's something in the personality, but again, personality is incredibly difficult to judge, and of course people can change immensely when they're under pressure: some will become stronger, others will crumble.
So yeah, Ferguson probably won't be Everton's next great manager, but only because of numbers.