Common App Essay

<p>Hi I just a few questions about college applications and the common app: </p>

<p>1) If a school has the deadline for early action at a particular date, but says the all tests scores are due at a later date, does that only apply to regular decision or EA as well?
2) If I apply EA to a college using the common app and the common app essay, but later when I apply to a different college through regular decision, it it possible for me to edit my essay?
3) If I apply to a school on regular decision but send in my test scores a few weeks later, will that affect my admission process? because I heard for rolling decisions you need to have everything in, but I don't really understand what rolling even means.
any help will be much appreciated!
Thanks</p>