I haven't played FQ2 in a while, but I'll try to adress each question.

1)Can't heal the indian and the tree, those unicorns won't look at me.
You CAN heal the indian, and after you heal the indian you can heal the tree (although the indian won't give you anything)

2)Can't pass the beefhead (what a stupid creature to have in a fantasy land, Michael Ende is turning in his grave).
Hahaha, you'll need to use some cooking techniques to beat this guy. First off, however, you'll need another item (I'm not sure, but I think you get it in exchange for something at the store) and you'll need another liquid in that bucket.

3)Can't pass the fire drake.
You'll need a weapon first, and then you'll need to use clever strategy.

4)Can't enter the tower
You can't yet, you need an item you get much later.

5)Can't turn blue ball red.
Again, you'll need to get another item first. Don't worry about the ball until you kill the fire drake.

6)Can't open the gate behind the volcano
Don't try. There are two gates I can remember, one you can only open from one side (it just provides a shortcut) and the other you can't get through until much later in the game.

7)Can't understand why on earth would I need that tiny, useless silver coin.
You'll need it for a fight near the end of the game.

8) Can't spread my arms and pinch my nose at the same time.
Eh?

9) Can't get the hang of English spelling (sorry about that).
No problem, I could understand you perfectly fine.

Hope this helped.