What about this slant:
ST was peddling Italian goods for RB, the home invasion was not connected to RB but they stole goods that ST was supposed to be moving on for RB (has anyone ever valued the watches and clothes?)
RB is annoyed that ST owes him for the goods that were stolen, ST doesn't see it as a big deal, its only a few watches, RB gets increasingly mad, a fight breaks out at his house on the 7th, gets out of control, AD is there, gets involved, escalates and next thing ST is accidently killed.. The guys panic and hence the chaotic cover up?
Your theory could be possible that they were dealing in stolen goods. I thought that ST brought the watches and designer bag back from Italy, but he could of had other watches from elsewhere? I suppose ST would have had proof of purchase as to what he bought when overseas, with an ATM card & that would be on bank records?