Apparently, my college counselor is REQUIRING all the seniors to complete their apps(essays, recommendations, other requirements) done by September 30th, regardless of whether the students are applying early or regular. According to her, the earlier you send in your apps, the more colleges will favor you? Is this true?
Depends on the college. Colleges with rolling admissions or those with first come first served scholarships could be ones where it is advantageous to apply early.