Is there a list of supported gestures somewhere?

If you check out the documentation on the panel tag, it will give you a general idea of action triggering gestures such a onswipe and onrotate.

right now most pinching is supported with the attribute called zoomable that is an extension of the panel.

We currently do not have a list dedicated to gestures, but I will take this request under consideration.

I noticed an onhover event. How does one hover with iPad?

onhover allows for you to trigger an action when you drag another object over an object or drag your finger from a down state somewhere else over the object.

On the pinch, I want tot be able to enlarge something by pinching, it doesn't sound like this will be possible in wire?

If you have the image set to dimensions smaller than it actually is (limiting it by making it a child of a smaller panel for example) and then invoke zoomable, you should be able to pinch out to make it "actual size".

When zoomable is set, the object will pinch zoom within its bounds. Zoomable can’t live at the root, you must assign at least one parent to base the zoom on.
Value = yes/no