Transferring to CCNY?

I’m a freshman student currently her second semester at a college in New York. I submitted a transfer app to CCNY for fall 2016.

High School GPA: 95.6/100
AP Scores: 5 - Calculus, 3 - USHistory, 3 - World History, 1 - Physics C:E&M, 1 - Physics C:Mechanics, 1 - Statistics
SAT Score: 2050 (620 Reading, 640 Math, 770 Writing)

College GPA: 4.00/4.00
College Extracurriculars: IEEE
College Major: Electrical Engineering
Experience: Research assistant summer 2014

I submitted my CUNY application (with CCNY listed first) for the fall 2016 in November 2015, and I sent along with it a personal statement, a transfer essay, a resume, AP scores, SAT scores, high school transcript, and fall 2015 transcript from my current school. Only thing I didn’t send was a recommendation.

I called CUNY this week, and they said I will receive a fall 2016 decision by April 15. If I don’t get in, I will try to do the walk-in admissions thing in July. You can’t apply to the Grove School of Engineering (which has my major) through walk-in admissions, but you can apply to the Division of Science (which is the closest thing to my major).

Would it be possible to come in as a division of science major and then transfer into Grove after a semester? Or come in as an undeclared major (if possible), and then transfer into Grove after a semester?

Also, should I send in a recommendation letter before April 15? Will it actually help my application or just delay it?