You have made a lot of good points!
After all, there has been no evidence that a crime has even been committed.
Only speculation based on behavior and actions that may or may not be true.
Concerning him not notifying Barbara's son right away, there may be a reasonable explanation for that.
Earlier it was mentioned that LE had possession of Robert's phone in the beginning of the investigation. Do we know if he even knew Barbaras son's number? Maybe the wrong number that was given was the number he thought it was, but LE had to search through his phone to ultimately find it.
Or maybe he was just so overwhelmed with what was going on that he assumed another family member had contacted Barbara's son.
Apparently they didn't get along , and for all we know Barbara hadn't seen her son for years so he just didn't think about it right away. He must have been overwhelmed between talking to investigators, notifying family members, and trying to figure out what happened to his wife. Not to mention dealing with his grief.
As for him hanging out in certain places and staying in his RV, or leaving the dog at the kennel, I'm not sure if any of that has been verified either. And if true, we don't know the reasons for it. Maybe he finds comfort in the people who he is hanging out with at the casino (if true) and he can't stand being alone in his house because Barbara is not there.
Maybe he feels as if he can't take care of the dog right now. Or maybe it's just a painful reminder of his wife.
Considering that he is a victim, he has been getting a lot of criticism and accusations that he has committed a crime when there has been absolutely no evidence that a crime even occurred.
In fact LE has stated from the beginning that they do not suspect foul play and as far as I know that has not changed.
Of course if there is evidence of a crime that points to him I certainly wouldn't have a hard time believing it. After all, we don't know these people at all and don't know what evidence LE has or if they have had any success following up on leads.
We just don't know yet.
I just hope they can find out what happened to Barbara, and if it does turn out someone is responsible, that justice is served. The family at least deserves to know what happened, if that's even possible at this point. Imo