Why?

Why dont tony's soldiers, gangsters, capos etc call him "boss" or "Don"

he IS the boss of the family after all...

Technically, Junior is still the Don, but with his condition Tony pretty much runs the show. Even still, however, Tony isn't officially the Don.

I suspect that "Don" is too formalized for today's Mob.
And I have heard Tony's guys call him "boss" plenty of times. Paulie and Furio have called him "boss" often, and I've heard guys like Bacala and Patsy call Tony "skip", short for skipper.

Tony's crew often refer to him as 'Boss'. For example, Paulie Walnuts ordering Bobby to be Santa in 'To save us all from Satan's power'.
What i want to know is WHY is Big Pussy's reflection shown in the mirror in the episode 'Provashi, Livia' (while Furio and Paulie are talking at Livi's wake and Tony opens a cupboard with a mirror on the door).
Please tell me someone else has noticed this!!!!!

I had to rewatch in when i saw Vincent Pastore in the credits to find that reflection

I guess maybe their trying to show that during times of death, Tony is still greiving the betrayal and death of his best friend.

As other's have nswered, he is sometimes addressed by his soldiers as "Boss" or "Skip."

But I'll go one better :

Why is it that Tony, who is a Boss, goes to meetings and travels around most of the time withOUT a bodyguard or an associate? I find this detail an overlooked one by David Chase and it makes things very unrealistic at times. Especially this past season when they were on the verge of a war. No Boss would ever go around from place to place without having a Bodyguard with him, especially on the verge of a war! However I still love the show and Sunday nights seem empty now that the season has ended. I'll have to watch season I over again.

Don Cardi

I pretty much agree with you.
Then again, when the New York situation was heating up in Season 5 Tony started using a bodygaurd on some degree (can't remember his name but he was a pretty huge guy).

That was former NFL nosetackle, Tony "The Goose" Siragusa playing the character, Frankie Cortese.

Maybe tony's dead friends came back to taunt him. Ghosts...