That dude didn't really know what he was talking about...if he was actually talking about orders. You can probably get away with it on a pax manifest, however the pax terminal @ Hickam will raise eyebrows when you turn in a pax manifest from the Travis pax terminal AND a manifest that the crew typed up (with just you on it). As long as you are on leave, and are entitled to space-A, you should be ok. However, this guy (and maybe you) might get some heat for circumnavigating the space a 'sign up list'. Especially if the jet is full.
Like was mentioned before, as active duty on leave, you will be pretty close to the top of the list (ahead of all the ORFs). When we're carrying 70+ seats to Hawaii, we rarely fill every seat as well. SUU-HIK is one of the most flown routes in AMC. You will have 0 problems making it there and back.
If you have a choice, fly on a -10. We're a much quieter/comfortable/quicker ride. Unless we're dragging Hogs.