The two hour rule for small twins (less than 19 seats) was only introduced into JAR-OPS a couple of years ago. Before that there was no restriction even for commercial ops. If Netjets are going direct to the Caribbean, it may be that the Portuguese have not yet brought their national rules into line with this bit (JAR-OPS is at present only an agreement to align national rules); or they may have allowed NetJets the three hour facility. That would allow a GIV to get straight across.
To go back to one of your original questions, a 604 would need a tech stop in the Azores for the shorter route, or Gander/Goose for the two hour rule. The salesman will try and tell you otherwise, but their figures are based on straight range with no contingencies!
