Last time I moved when I had a petition pending, I had to fill out all thee forms by mail. Now I hear than you can fill out the AR-11 and notify of the address change regarding the petition on-line. Does this work this way? Can I do both on-line? I do have the I-865 ready to go for my wife, but I am waiting to hear if I can do my part on-line.

The AR-11 can be e-filed as far as I know.
The I-865 still goes via snail mail.

What's the third form you refer to that you previously filed for a move?

That woud be notification that you have a filed petition.

Ah yes, the ole' useless letter one is supposed to send in.
A lot of good it did.