It's a myth that you can trust "blood" more. Loyalty doesn't really come from being related. It doesn't hurt I'm sure but it's not the litmus test on trust.
It's important when you are in a position of power to have someone who can represent you. Especially, of course, if you are mixed up in this shady business. It can keep the direct connection between you and your sorry deeds apart. Makes it hard to track who ordered what. Limits your exposure.
A.J. is trying to piece things together about his dad's business. His friends and girlfriend seem to be more interested in his family's illicit status. Be sure your friends like you for who you are. It's important to find people who care about you.
Also, A.J. gets a lesson in humility. A.J. didn't realize how affluent his girlfriend is until he visits her at her Father's home. Carmella had bragged to A.J.'s girlfriend about an expensive figurine she had that cost $3,000. But, it turns out his girlfriend had Picassos on the wall. It's considered inappropriate to brag about the cost of your possessions. Despite all the money the Soprano's have they don't really fit in with the money types. This is a clear class distinction that played itself out with this boast.
Tony finds out in this episode that Gloria committed suicide. This shades his decisions throughout this episode. It forces him to question how he treats others asking in a couple of situations, "What am I a toxic person?"
First, Artie tries to get into loansharking through Tony's associate Ralph. Ralph doesn't lend Artie the money. Ralph's not a nice guy. He made a correct calculation that if things went badly Tony wouldn't appreciate the consequences to his long-time friend Artie. He dresses it up a bit and tells Artie, "If you don't pay me back I won't be able to hurt you". When Tony finds out he is upset that Artie didn't ask him first. Tony is feeling very vulnerable at this point still reeling from the realization that Gloria killed herself. He lends Artie the money. Of course, the guy who he lent the money too refused to pay him back. Artie tries to get tough with the guy but the guy ends of pulling his earing out of his ear and hitting him. So, if you aren't a tough guy you are not going to become one by practicing your speech in front of a mirror Artie. He's so distraught he calls Tony to tell him that he has taken a bunch of pills and is ending it. Fortunately for Artie Tony is really in turmoil over Gloria's suicide and he happens to really love Artie so he gives him an out. Tony is wise to let Artie know that he can't tell anyone he left him off the hook. Tony's reputation is on the line.
Second, earlier in the episode Tony has dinner with his sister, Janice. Janice has had a history of mental issues and Tony is wanting to check on Janice and at the same time relieve himself of any guilt he has felt over her past mental anguish. At one point Tony asks about Janice's relationship with Bobby and Janice thinks Tony is going to say something negative. Again, Tony says "What am I toxic person?