can a figure with flying and super strength taxi two people at once? Some people say yes, others say no, so I just wanted to make sure.

No. A flyer with Super Strength can carry an object and a figure, but not even another figure carrying an object.

Just to clarify since web's wording might have been a little confusing, you can carry either a figure, an object, or both. You can not carry two figures nor can you carry a figure carrying an object.