I wouldn't read much into the Delaware registration or address. A lot of planes are registered there relative to the state's population For example, 105 out of the 1600 or so Cessna 172Ps are registered in Delaware. Only 111 Cessna 172Ps are registered in our most populous state -- California.
There's a simple explanation for it --- Delaware has no state sales tax and is very reluctant to otherwise tax nonresidents. They are happy enough collecting registration fees. I wish New York were more like Delaware in that respect.