You should definitely be receiving SMS message notifications on your watch and be able to reply. When you say that you want something that syncs, do you mean that you want to be able to open the watch app and access old messages? If so, unfortunately you can't because that's not how SMS works. SMS message are delivered to your phone and not stored on any servers. The only service that allows this kind of behavior is Apple's iMessage because it intercepts your texts and uploads them to Apple's servers.
Regarding app support, one big difference between Android Wear 1.x and 2.0 is that you have to install apps directly on the watch. Go to the Play Store app on your watch and you can search for and install app. Also any app on your phone that has Android Wear support won't be installed automatically on your watch, but it will be listed at the bottom of the main Play Store screen to allow quick installation.
You ask "Why aren't there proper apps for things like Facebook, Twitter, Instagram, Whatsapp, etc?"
I could see What'sApp, but what would you want to do in a Facebook, Twitter, or Instagram watch app? You don't need an app to get notifications. Are you actually trying to browse you feed/timeline?
In general Android Wear isn't trying to put your entire phone on your wrist. I think the assumption is that most people don't want that. Android Wear is trying to give you quick and convenient access to your notifications, including sending a quick message response, basic activities tracking, and Google voice assistant. Anything more than that and they except that you prefer to use your phone.
Messaging - I downloaded the Messages app, it works perfectly as in it shows my conversations and allows me to compose messages without having to wait for a notification. However, again, I end up having two messages apps on my phone (I'm okay with this, I can disable notifications on one of them and hide it). and as I mentioned earlier, apparently the Messages app by Google doesn't support gifs by SwiftKey or something.
In regards to Whatsapp, I want an app that, again, lets me look at my conversations and compose messages without having to wait for a notification to pop up for me to reply. One time I got a Whatsapp notification and I accidentally swiped it away so I had to pull up my phone to reply when I easily could have done so on my watch.
Also, I just noticed this. The keyboard on the watch doesn't let me type up a message and include an emoji. Why?!
As far as other apps, let me tell you what I like to see and you tell me if it's reasonable, and if there's anything like it right now:
Social media: I'd like to browse timelines. Why can't I read tweets on my watch? Why can't I go through Instagram and Facebook feeds? The screen supports pictures and colors, why can't I browse them?
News: One thing I consistently do on my phone is look at top headlines. Once again, I can't seem to get the CNN app to boot up on my watch, although the app description clearly shows it's Wear enable. Why isn't there a Reddit app where I can also look at the front page posts?
Banking: Why can't banks have apps that show balances? I don't want to my business on my watch, but why can't I get a quick glance of my balances on my watch?
I don't think I'm asking for too much. I don't want Youtube on my watch, I don't even want games. But for some reason, it appears there are more crappy games available for the watch than common sense convenience apps.
Sorry for the long post.
/endrant
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