The very low amount of money is the biggest puzzle to me too. It is the primary reason I lean toward 'walk away'. I'm willing to be convinced otherwise, but why did he leave such a very small amount of money? Where did the rest of it go?
One of the theories I consider fairly strongly is that he invested in off- shore investments and had overseas accounts ( For example, Grand Cayman Island is or was a tax shelter haven, traditionally Switzerland was as well until after 9/11).
There's enough missing links in the money chain to believe there
could have been sizeable deposits/ investments in offshore investments. Unfortunately for his tax shelters which were legal, offshore banking in the USA became both costly and time- consuming to retrieve after the US laws and tax laws changed drastically following 9/11. There were also limits put on foreign transactions, which a direct transfer or series of direct transfers would have probably been subject to.
It might have taken a prudent and careful person 4.5 years to set up a new living plan that included accessing a sizeable amount of savings and other personal investments and possibly relocating somewhere else and enjoying the fruits of his labor.
One thing to remember: He may have left with the help of relatives in high places in Slovenia, stayed gone long enough to move the hidden money to this trustworthy group of people outside the country that he had lifelong ties to, stayed with them until the case had lost steam.
Because he likely did NOT anticipate ending up on a national Missing Persons database and watch list, either relocated to parts unknown in a foreign country as a backup plan where he could have dual citizenship ( in Slovenia), or headed to the Pacific Northwest, which we know many people have done since the area was able to be traversed by outlaw gunslingers and those who wanted life in the wilderness at least a century ago, living a low visibility life while still being able to see his daughter and her family as they grew. He would know not to be seen out and about, especially with his family, and he would use an alias in the US, at least. He probably also could have settled in Slovenia, the country of his ancestors.
There are SO MANY things he could have done other than been murdered or committed suicide and all are based in general fact, and some are based on his singular life, not a general plan for the public on how to disappear.