I think the best attitude to call AppleCare w/ is a patient and understanding one but yet firm and assertive.
Like you've read, I have more than one issue tha required looking at and I basically told them I had the Apple Store look at a few mechanical issues which they felt needed repairs, thus the call. Told the rep how much I loved mbp but had a few concerns. At which point some reps will ask if you have AppleCare and ramble on to sell you one while others might just be straight w/ you and ask what the problems were.
The rep I had made me toy w/ the idea of AppleCare which I politely declined by telling them I will highly consider it towards the end of my warranty. But otherwise I told them I had a really obvious static interferrence tpye whine coming from the left speaker and whenever I used any 3D apps, I would be greeted w/ what sounds like a dying/struggling fan from the right speaker. I didnt give them an epic story how many people on MacNN had theirs at what temp blahblah. Keep it simple and straightforward. I knew once the logic board was replaced that the heat wold go away, so I didn't even mention the heat. Then at which point they should send you a box to you.
I wasn't aggressive or demanding in such a way that made the reps feel bad. Just call being happy, slip in what you need to say
Unfortunately when you send in anything, they only investigate it, doesn't warrant any repairs 100% unless the problems ultimately requires repairs. I had three/four issues w/ my mbp, but only the fan and whine were the main problems which the fan didn't even get fixed.
And sadly I WILL be sending it back in again soon because while the fan noise is not loud enough for the whole class to hear, the people around me can. It's sad to know i have to send it in more than once when I explicitly said I needed that fixed.
Note: When needed to describe the issues you're having, make sure to be VERY percise if the problem you have isn't a standard one.