Tony was probably against his sister dating Richie. IIRC, Richie was house shopping with Janice at the same time he was looking to take out Tony as the boss. If Richie took over the family, would he have dumped her? Seems that he was dating her before Tony took over the family.

If Tony got whacked before Bobby B, would Bobby have dumped Janice? I'd say no. However, I agree that this relationship paid huge dividends for Bobby. He even beat up Anthony without any outward repercussions.

Ralphie was making a ton of money, yet wanted to move in with Janice. Was he a capo at the time or was dating Tony's sister going to make him a capo?

Janice was completely miscast. If she was going to be the irresistible milf, they could have picked an irresistible milf to play the part. For example, Sharon Stone was a great choice to play Ginger in Casino.

You shit-kicking, stinky, horse-manure-smelling motherfucker you! If you ever get out of line over there again, I'll smash your fucking head so hard you won't be able to get that cowboy hat on. You hear me? Fucking hick. -Nicky (Casino)