My additions...
2) I didn't get the little card to be filled in for the 'free' canapes and when I called to get them ordered on my first Elite trip, I went through hell. Even though my steward didn't give me the form, it was my fault for not knowing about it. You have to order them the day prior, and you only get them on formal night and if you fill in the special Elite form. Stay on top of it if you don't get it from your steward on the first day.
3) We informed our steward which things we wanted switched out in the bar, and it was done the first full day.
5) I am a laundry service feind!

I send out my stuff every single day on regular service, so it comes back tomorrow night if given today. Express is also free, so I turn stuff in Express on the last day so I can have an entire suitcase of clean clothes on my way home. The only thing that comes home dirty is the clothes we wore on the last day. And I do pack less, but it's still tricky to pack the right number of things because of the 'end of the next day' time thing. I'd say I cut my packing by 1/3 on a 7-night cruise. But I was still a bit challenged and had to send out Express one time midweek for my hubby to have dockers to wear to dinner.

I've had no problems with the dry cleaning of the formalwear either for free.
The only thing I sent out that came back not as wonderful as when I sent it was a bra. I guess for that kind of delicate thing, you shouldn't be a laundry feind. LOL! I had so much success up to that point though, I decided to try it.
The paper laundry bags don't hold a lot and are not as sturdy as I think they should be. Therefore, piling up your laundry is less convenient than sending out out a little at a time every day.
Also, on my last Princess cruise the steward actually brought me laundry tickets that were pre-printed with Elite in yellow, so I didn't have to write it manually.
And if only one person in your cabin is Elite, be SURE to send out the laundry under the Elite person's name. I've heard stories of folks sending it out under the wrong person's account and it not being free. How

is that?
7) I had Traditional Afternoon Tea delivered to my cabin once, just to try it. I thought it was fun, but prefer the atmosphere in the main salon better like f-mattox said.
Suzy's side point - I'm sure you already know this from being Platinum, but be SURE to buy the interent minutes 'package' and don't start paying 'by the minute' before you get your package. It's a huge amount of difference in minutes you'll end up getting. Doesn't matter that you might not use them all. Also, if you're a WiFi lover, the free minutes work for that on ships that have SeaMobile installed now, so it's all good!
Cheers!
~Suzy