You're welcome,

1.
There are a few ways.
You can make a "Symbol Animation" that toggles between two symbols (or more).
Symbols are objects that you draw in the drawing "symbols.g" and give them a recognizable name.
Then you make the symbol animation in your picture and tell what symbol to show based on what tag value.

An alternative would be to use script (PowerVB).
To make an object invisible, you could move it completely out of the screen using script and then move it back again when it should be visible.
This is commonly used in FactoryLink tooltips in Application Editor graphics.

2.
To make a simple go to button, you draw a rectangle in the Application Editor andin the toolbox click the icon looking like a OK button. This is the button animation.
Here you select the action type DRW and then in the "Value" field type the name of the picture you want to open (without the .g extension).
You can then write some text on top of the rectangle to give the button some text.

3.
There is no built in toggle tag animation.
Here you need to write script that reads the current value and toggle the value.
So: on MouseClick, if tag=0 then tag=1 else tag=0

I hope it helps.