I have some questions about tapered (non-constant chord) wings. I did a search, but if some of these have already been "asked & answered" please excuse.

1) Why is a tapered wing more efficient than a constant chord wing?

2) I have read here that a tapered wing seems to "think" it has dihedral, why is this so, and is there a rule of thumb that says "so much taper approximately equals so many degrees of dihedral" ?

3) Is a tapered wing more susceptible to a tip stall than a straight wing of the same area? How to get around this?

4) What is the amount of taper from root to tip that will achieve the max. possible efficiency while being resistant to tip stalls?

5) I have noticed that pattern planes almost always have a tapered wing. Is this a case of form over function, or does it result in any advantages such as the above, and also more "precision" ?