Well, well, Ken, ok I read it all and voici:
First, Columbia won't likely go to ISS as it is too heavy, but you suggest perhaps a lighter payload anyway.
Why must the Shuttle tourists go to the ISS, BTW? If there are 15 of them, they'll be a nuisance more than a bless to the ISS occupants. An unmanned platform with large solar panels could do the job.
The Russians (or was it MirCorp) have proposed 2 tourists for the 3 seated Soyuz, but WITHOUT an ISS docking, and spending 1 week in space.
If there are 10 passengers inside SpaceHab during liftoff and return, how about safety measures and evacuation procedures for those away from the mid-deck? Maybe, at that point, the 15 passengers shouldn't wear a pressurized suit anymore.
And the EVA with MMU stunt? Only a few could do that and they'll need a special training beforehand.
What would be needed is not only a large window on the SpaceHab but perhaps especially an cuppola kind of design, with a much better 3D vision for the passengers (removing the need for an EVA).
Anyway, ça fait des mois qu'on n'avait plus de nouvelles de toi. Welcome back.

Raoul