The "the Wand chooses the wizard" thing doesn't make any sense in relation to the Elder Wand.
That Wand doesn't choose it's owner. It submits to whomever "wins" it.
Not really true. It resisted Voldemort, and actually worked against him in Harry's favour. It chose him, I guess..?
I carved out the rough shape for the wand, now to finish it up! All done with a pocket knife and dremel tool
But not necessarily because Harry was stronger, rather because Harry had previously taken malfoys wand, after Dumbledore had allowed Malloy to disarm him of the elder wand. Its allegiance to Harry rather than Voldemort was really only on a technicality. :shrug: