I am too late to answer, but at least you know now that the mouth opening, body raising thing is normal.
I ADORE beardies. I had a few of them waaaay back when I had a lizard pit in SA.
And I am PROUD and PLEASED to advise that as of Saturday I will be the proud owner of two central beardies

$30 each and only an hour from here, though I had to get an import permit! ARGH
I am pleased as punch to add my beloved fave species of lizard to my collection of one captive childrens and one 'I think I'll just live in the house thanks,not a tank' childrens.
NB: When I say 'add' to my collection, I do not mean ADD to my collection....hehehehe The beardies will be away from the snakies