Some small questions

* Yes, you can rotate items. I forget the keys (check the Control option screen), but the mouse wheel pops into my head for some reason.
* You don't heal. Hopefully, in future updates when Food is added (for now you can kill animals, but there's no "drops" nor can you get food from them) you'll be able to regain some health. (Remember, this is alpha). For now, that "health" bar you see- consider that how much "life" you have left. When it runs out, you die, but can respawn.
* There no water in the game yet (and therefore no "thirst"), so you don't need it, or could use it anyway. As I understand it, there is some water in a swimming pool somewhere up above the clouds, but that's it. (I'd consider that pool a rumor). Don't worry about water (or lava, etc.) for now.

Basically, there's a lot missing for now, but there's a lot that's gonna be added. As you found out, this isn't the same as MC. It doesn't have the same things or work the exact same way, and what it does have is way better (and "different"). I had trouble at first, but found that forgetting that "MC mindset" helps. This game is far better than that one.

I use the arrow keys to rotate.

It's a known bug, falling through the world. Press F2 while falling to fly. My servers are listed, but there is currently a bug that causes some connection issues.