the 4600 5 pax calculation is funny. As even including the conversion the bird has my T/O weight of 16.300lbs. And I never ever had seens a beechjet400 with lower empty weight as of 10.600
10.600 + 2 crew (160lbs each) = 10.920
+ 4600 lbs fuel (Beechjet400a can carrie up to 4912 - yes we all count 4.800)
15.520
5 pax 180lbs = 900lbs
16.420
And no one flys to Bermuda with no luggage = 150 lbs
16.570lbs ...
+ taxi fuel + conti +...
So what your calculation is rubbish