1> about one blade
2> various on what you want to do
3> depends on where you are flying
4> PT and Mejzlik are considered two top contenders for CF props
5> Thank goodness you gave us this option!
The main reason for 3 blade props is sound.. they are quieter.
2 blade props spin up quicker and a bit better, but they can rip and can be very noisy (depends on pilot too) so many fields have sound requirements that require a 3 blade prop (and cans) to stay within....
That help?