I hope more will come out on the coin theft, I have a feeling he didn't act alone. For example, where were the coins during the year since they'd been stolen? I think someone had them on St. Martin.
My speculation is he's the type of guy who, having discovered the lifestyle of sailing and hanging around in laid-back tropical locations, didn't want to become a 'wage slave' to support his wife and child. Plenty of those roaming the world, they depend on various schemes to try to make money, like buying a boat or condo and fixing it up to sell, picking up odd jobs compatible with their lifestyle, going home for a few months to live off Mom and Dad while working to save up some money. They may be tempted by opportunities/offers to make a bundle quickly by smuggling or stealing from a rich guy's boat.
In my mind, that doesn't automatically lead to killing your wife and sinking a boat. It's possible he had a guilty conscience and fear about getting caught with the coins, and that could explain his unwillingness to speak much to the press and made an accident appear very dodgy. I also don't think he ever had the intention to settle down in Florida, and didn't want to be tied down by Isabella's relatives, and was a selfish, insensitive jerk to them.
I really don't know what would've happened if Isabela hadn't died, and how they would've resolved this impasse about where to live. It remains possible that, unable to persuade her to leave Florida, he decided to resolve the situation and make money off insurance at the same time. But it seems an insane plan unless there's some other factor that made him feel utterly desperate. And it's very unusual, to be honest, for a man in that situation to want to be burdened with a baby.
