To progress a track on Windows Phone, you press and hold the Skip button. The same goes for rewinding a track using the Previous button.
To try to cover some of this, I'll star with the simple answer: I would wait until the next hardware refresh. As you already see, Android is in the process of refreshing its hardware with the HTC One, and the new Galaxy device from Samsung is due to be announced in about 2 weeks. If this was November, I'd say get the 920, but if you get the 920 NOW, you might see it replaced with a better device in a couple of months (seeing as it's not uncommon for devices to have 6-month life cycles, and the Lumia 900 was refreshed after about 6 months, to the 920).
To cover those 9 points you had previously:
1. Fluidity: For the most part, the OS is VERY fluid. Some apps might not be at times, but I've never had an issue of hiccups or slowdowns with the actual OS.
2. I cannot offer anything on this. Aesthetics are 100% personal. I like the look of the OS as a whole, but that's me. I prefer using an image as my lock screen over my wallpaper like on Android, where the icons cover the image. However, it's really just something you have to figure out for yourself. My only complaint is that they need a color wheel for live tiles, rather than only giving you about 20 options to choose the live tile colors from.
3. I tried texting a little on my brother-in-law's Galaxy S III, but only once (he left the phone at my house and my sister texted him). I hated the keyboard myself, and I felt that the spacebar was WAY too small. I still feel like Windows Phone would benefit from a bigger one (I hit the lower row of letters quite frequently while trying to hit the spacebar). As a whole, I'd say that the Windows Phone keyboard is MUCH better than the stock Android one (I had an HTC Droid Incredible for 2 years, so I have extensive experience using it), both in typing experience and predictive texting. I will say that I think SwiftKey (pretty much the top third-party keyboard on Android) had better predictive texting than Windows Phone's keyboard, in my opinion. SwiftKey seemed to really catch on to my vocabulary quickly, where as Windows Phone STILL misses a lot of what I want to say.
4. I cannot help on that one, as I don't do this. OneNote is allegedly good and built into the OS, so that might be good for you.
5. I actually hate the calendar. It defaults to opening on a current day, not the month. It also seems to put the text in calendar view in another language or something, which is annoying. I don't use my calendar, but I was just trying it out a little, and noticed that. So, again, it might work for you, but I don't use it, so I don't know if it's good. There is likely an app available that will provide you a good calendar on Windows Phone AND Android, though.
6. That's something I never had on my Droid Incredible OR my Lumia 920, so you needn't worry about having that happen. I have had the browser act up a little on occasion, though. It'll kind-of lock up if I try to rapidly press Back to close the browser, which requires pressing back until you get to the page you had opened initially.
7. I LOVE the camera on my 920. For starters, the camera button is a great thing. You don't need to open the phone and find the camera application, then make sure you don't accidentally hit the wrong icon (sounds like a silly hypothetical, but I've done it many times--open the wrong application). The Lumia 920's got the BEST camera on a smartphone (outside of the 808 PureView), no question. I've compared mine to my brother-in-law's Galaxy S III a couple of times, and the low-light performance wasn't close AT ALL. I don't do any photo editing or anything, but there are some basic settings to help you out with getting a decent picture (for example, I've taken pictures of my TV, and turned down the exposure to make what was on the screen reasonably readable). Oh, and I like opening the camera, then having a button to switch to video, rather than Android's preference to have separate applications to start picture and video.
8. This depends on your desired use. Google Maps is more detailed and has StreetView, which Nokia Maps (now called HERE Maps) has nothing to counter. However, the nice upside to HERE Maps (I hate the rebranding, I really do) is the offline maps usage. My brother-in-law said that Android only allows the downloading of 88 MB of map info to his Galaxy S III for offline use. It covers about 2 hours of driving, I think. However, Nokia allows you to download an entire country (or multiple countries, I guess). The United States is about 2.5 GB. In December, we had a bachelor party for my brother-in-law, and so I downloaded Illinois and Missouri to my phone so we could find where to go without data usage. IT was about 250 MB of storage to get both states, but it was nice to not be using data.
9. This really isn't something I can say is better or worse than Android. It's texting, and the only thing that'll make one better than the other is your keyboard preference.