Hi Joshua,
Welcome aboard to our humble little home. First, you don't enlist as an officer. You are either enlisted or an officer, not both.

An Associates Degree will not get you into OCS, for that you will need a Bachelor's. No degree of any level is a wasted piece of paper, you earned it, be proud of it, keep going, get the next one. Even if it is while you are active duty, we have plenty on here that are doing that right now and plenty who have done it. Education is never a waste. OCS is highly competitive, numbers have been mentioned before and it was a phenomonally low number of people selected off the street, per se. It is far more beneficial to enlist, work your way up in those ranks and then go to OCS. You will find you stand a better chance.
You say a CG recruiter contacted you but made it sound like Coasties aren't in demand. Quite the opposite, the CG is a very high demand job right now. Offices are turning away qualified recruits because they have so many. Now that is not to discourage you but to point out when you get in touch with a recruiter, leave an impression. Make him think, "Hey, that kid Josh, I spoke to him a couple of days ago & now he is emailing me wanting to set up an appointment. Let me respond to him & get him in here, he is a good kid!" If you don't leave an impression, you will have just been another phone call. We have a few resident recruiters and all of them say "We don't hire the first 10, we hire the BEST 10!" Make yourself one of those BEST.
As for the training you mention, it won't really matter a lot. It won't get you advanced any faster or truly looked at any closer. You don't want to go into that sort of debt and it doesn't count. I won't say it wouldn't at all peak an interest in you, but to the tune of $15,000... I'm not sure it would peak that much interest. Save your money, if you are selected for OCS and eventually flight training, the CG will teach you!
Congratulations on your engagement. Is your fiancee supportive of this decision? I can almost wager my paycheck she has a million questions bouncing through her head... please tell her to join us. This forum isn't only for active duty members or those trying to become active duty. There are some great spouses, moms, dads, friends, active duty members of varying ranks & rates... have her sign in and ask questions about things that might be on her mind. For you it is career questions, for her it might be life & home questions.
You asked some other stuff that I will leave to people more in the know, like I said we have a wide variety! Try gocoastguard.com to find a recruiter near you and start calling or emailing. It isn't that they aren't interested in you, there is just a lot of interest in them (recruiters) and they have lots of calls to return. They will call you, just remember be a stand out among their phone calls.
Best of luck & again Welcome Aboard!
Macie