I'm a 1/C MIDN on the Marine Option side. I go to OCS in about 2 weeks.
I see that there have been a lot of questions answered already, but I thought I'd take some time to add my 2 cents.
First off, I know about six or seven Mids right now who transferred into our battalion after a year of regular school, both University and Community college, who are doing just fine. It's all about how much you want to put into it, how dedicated you are to leading Sailors and/or Marines.
There are a lot of times you will make sacrifices that a normal college student wouldn't, there may be times when you wish you were a normal college student again, but on the whole NROTC is incredibly rewarding. It will test you mentally and physically, but if you're dedicated to success you'll have no problem.
Also, your NROTC experience will differ by what school you are going to. Different programs have varying levels of involvement. Also, the satellite schools or "Crosstowns" that are offered can be a great choice too. Our unit has two crosstown schools.
One thing that I'd point out is that due to the reduction of scholarship numbers, the focus of the applications is even more on grades and technical majors and less on leadership experience over all. Granted, they will still look for someone who competed, and displays strong work ethic and leadership potential. But now they are focusing even more on technical majors. and grades. Let's face it, the Navy is...well...technical. Mech E is a good one for that.
And your HS app looks pretty similar to mine. I would include any work history as well.
Also, a new NROTC Scholarship focus (similar to the Nurse specific one) is the new LREC which is where you would focus studies on a specific region, language and culture, but I think if you're in Mech E. the regular scholarship would probably be the best.
In my opinion there is no better leadership training you can receive than a good NROTC program. (and OCS/TBS for MO's) Shoot me an email if you have any other questions.
Glad to see I'm not the only ROTC-type on the forums.