I can answer that.
He already has a good shot out to about 20 feet.
He is more comfortable in a face up game than back to the basket.
His handles are decent in face up but suck backing his man down.
Cal had to play Bam under the basket because we had to have rebounds and putbacks... and a paper thin front court.
One other major thing most people don't know.. Cal plays his players so that the NBA drafts on upside. He knew KAT could play well on the perimeter.. same with Cousins.. same with AD. But Cal brings in all the NBA personnel, explains the immense upside, and proceeds to explain why the team NEEDS them to play the way they are.
And Cal explains all this to the recruit before they sign. There's no doubt he is king of maximizing draft stock.
Back to Bam. My opinion is he takes a while. He's a great athlete but not fast twitch. He'll get his shot swatted a ton the first couple years. Best bet is to draft him as a stretch 4 and cultivate him as such. He should be very good by end of rookie contract.