Many of the buttons have 5 states. But what are the.
1. unpressed
2. touched (note the icons sit a pixel lower in the button)
3. hover over
4. pressed
5, Unavailable
 
Is that right?

 

 
Eveb less clear when I look at Tungsten.
Do they have the same order in Tungsten as in Mercury?

The order is the same regardless of the actual pics. The OP seems accurate, but you would need to op-test them to be sure. Can color code the 5 totally different colors to test it. Off, on click, mouse over, on, and disabled looks accurate.

Some have 4 and 8 states, I numbered the buttons to figure is out...

You got it right. The way I like to think of it is (note I didn't list them consecutively):

1) OFF state
3) Hover over OFF state
2) Pressing OFF state
4) ON state
5) No project loaded or unused

For those that have 7 buttons the changes are:

7) No project loaded/Unused
6) Hover over ON state
5) Pressing ON state
Others are the same

For those with 8 buttons, they're like the 7 button scheme, but with the added multi-state button.

Pete