I finally upgraded tonight to Business Plat from Gold. With the $200 airline credit, its only $75 more than the $175 for gold. Not to mention the 50,000 or 100,000 points bonuses. A few questions for you Plat veterans:

1. What happens to the $175 fee I just paid a few months ago for gold? Prorated refund or do I lose it?
2. I am about to make an international airfare economy purchase on AA for a trip next year, I intend to use the 35% points rebate. Airfare is actually pretty cheap for my trip at $470 pp and there are 3 of us traveling. The way I see it, it still makes sense to use points instead of paying all cash with this rebate because I am using the points like cash, right?
3. I will also be purchasing a Mediterranean cruise vacation, so if I do that through amex travel, I earn 2x or do I earn 2x even booking direct with cruise line (its less than $5,000)? Also, has anyone used the Plat onboard credit of $200 for a balcony and know how to confirm I will get it?
4. Lastly, I already have loyalty accounts with SPG and Hertz, etc. The description of benefits only explains two scenarios, sign up for these loyalty programs or continue as a gold member with SPG without having to maintain qualifying nights. I am not a gold member with either; so what is the process for me to notify SPG and Hertz to elevate my status?
5. Any other "to do's" to maximize my new benefits?

Thanks!