one character sheet to start with. this won't prevent you from having a few important NPCs, if you wish. however, as the RP progresses, you can have more characters, or transition your NPCs into more prominent roles. 

to answer your other questions: those physical changes all sound fine. as long as the Talisman just keeps with one "theme", I probably won't take issue with it. additional items/equipment will exist too, I'll add a space for that in the bio. to acquire these items, just play along with the rules. if your character somehow has a ton of these smoke bombs, they must either have good connections, enough money to purchase the bombs, or a skilled enough artisan to make them from scratch. maybe they were in another Guild before jumping to this new one? etc.