Nope!
Employers don't look at ACT scores. Community colleges usually offer open enrollment for anyone with a high school diploma, and don't require ACT scores. Four-year universities vary widely in what they consider scores acceptable for enrollment.
All colleges have different timelines for when SAT scores are due. Go to a particular school's website and under admission, you can find out their specific timeline.
Yes. The scores are sent to them from the testing service. Which score a school prefers is depended on the school and their admission process. At this point, most schools will look at either of them, but check with their admission office to determine which they want to see.
It depends on what level you're taking. There is a manual for NYSSMA that lists all the choices of the piece you'll be playing.
Bowdoin, Bates, Hampshire
Most colleges want students with both good test scores and strong extracurricular backgrounds.
Colleges may take up to two weeks to receive the test scores. Although the sending of scores is done electronically, it takes a surprisingly long amount of time for CollegeBoard to actually send out your scores, depending on the amount of requests.
Most colleges will accept both, but you will find that, typically, colleges on either US coast will prefer the SAT and colleges are more inland will prefer the ACT.
Yes, it is available for an ukulele.
April 24-25
Yes. But you can choose not to have them sent.