One issue I had that may help you is the launcher interface. This swipe both left or right for a new watch face on AW 2.0 is ridiculous. So I found this launcher that lets you swipe from the right like you used to do and also hide/favorite apps, etc.
Battery life is hit or miss for me. Def doesn't get me through two days like it used to.
Absolutely slower to do anything than it used to be, but hasn't gotten that bad for me yet anyways.
One thing I LOVE is that they FINALLY fixed the freaking music player. That was always a pain in the ass on the first version and you had to find a hack around depending on what player you used generally. Now it just works.
I've had mine for several months now, and to me it's just as comfortable as a regular watch, I've never had any problems with it.
As for your metal band question, coincidentally I just purchased one yesterday. It definitely adds some heft and weight to the watch, but I actually prefer that.
Sure. I bought that one :) I didnt use the included screen protector though.
EDIT: I'm in Canada so I bought that one from amazon.ca but I linked the same product from amazon.com.
I have always used this: https://play.google.com/store/apps/details?id=huskydev.android.watchface.blackclassic I used the free version for most of the time and finally paid after a month or so of 2.0.
I continually keep coming back to krona sunlight. It's the only app I've ever even thought about getting a recurring subscription to.
I don't know if it's really helping, but I feel better after launching and running this app on my phone. May as well turn off the ok google detect, but either pressing to activate or hearing your voice both are dog slow. https://play.google.com/store/apps/details?id=rocketstartups.weartaskmanager