You have some interesting ideas here. i want this mod to be real good, but i also want it to be reasonable to complete. Throwing in too many factors leads to the greater chance of bugs, but we're certainly not going to half ass it. I am looking for a middle ground as far as complexity of interactions between the silver hand and companions and enough content to make the mod worth playing. But the beautiful thing about this is we have nothing but options to choose from, its just a matter of choosing an idea or concept and sticking with it. But i will say that the dialog is going to be A+, @ohsorryoldhorse is one hell of a writer, and i'm sure he is reading this post everyday like i am. Once the CK comes out him and me are going to have a long sit down to iron out the details.
To make it simple there should be only one outside of Silver Hand member that is recruting new members. First he tests you companions style, and afterwards you will go with him to the dungeon that companions send you - instead of silver hand members there you could replace them with werewolfs - there's a trap scene that should be replaced. Maybe there would be more silver hand going to that cave and one would turn out to be traitor werewolf and he'd change, and only the quest giver would survive - or maybe Wilkas (the stupid brother) could be there and he'd attack SH, and you'd have to chase him and kill at the end of dungeon.
Just a new idea - after companions ride the SH hideout you just clean it - don't refill it with new members... after killing the leader of companions you'll get to move Silver Hand to their quarters, since the people of Whiterun would turn on companions once they find out their secret.
Each companion member of the circle would be boss at the end of each quest, and the npc that accepted you to silver hand and later become your right hand as a leader, turns out to be cursed with werewolf disease, and you recreate the hammer and go heal him. The blacksmith would help you with the recreation since maybe he didn't like werewolfs and it was not honorable way of fighting. The second brother would be hidding at that dungeon, or maybe he'd be the one that had oppened it.