A couple more minor points to consider:

1) Separate flaps & ailerons allows you the option of crow-flaps.

2) Flaperons 'up' for landings does give extra drag, but it also raises the stall speed, so you have to land a little hotter.

For some of your other questions about how much flap vs how much aileron etc - if you don't get the answers you need here, try asking in the aerodynamics forum, or drop an email to Bob Parks (I can send you his email addy if needed). Bob's a certified genius as well as a heck of a nice helpful guy

Gordon