omitting a control from being saved with the model (e.g. "password confirm")

Newbie here - hopefully a simple question.  Let's say I'm building a little registration form much like the one for the forum here:

example of a registration form

How with Orbeon Forms do you:

a.  Allow the password confirm to *not* be saved with the model instance data in eXist.

(I tried to omit the nodeset from the binding and that didn't work, and I tried to create a separate "dummy" instance in the model to bind the confirmation control to, and that almost worked but in preview it shows as a control not as preview, and when you come back to the form it's lost it's value).

b.  And where the checkbox label has an embedded hyperlink like:

     I have read and I agree to Nabble's <a href="http://#">Terms of Use.

Is there an easy way to include hyperlink markup in a label for a control?  Whenever I tried it seemed the markup was getting escaped and coming out on the screen instead of being interpreted as actual html.