This motion is FANTASTIC!!!! This is definitely a Swing and not a Hit. This dude could be the poster boy for Wrist Throw.
I'm not sure I'd touch this swing too much . . .
Could the driver problems be a FITTING ISSUE? That's where I'd start. This dude has great alignments in my opinion. As Mike O said maybe a touch more waist bend could help him keep the Right Forearm on plane a little longer through Impact.
I love the Centered Arc and stable head. Love the Left Arm Flying Wedge alignments at the Top. The Sweet Spot, Shaft and Left Arm are aligned perfectly for Swinging and that great Wrist Throw he executes. The only other thing I'd say is that looking at his finish makes my back hurt. Maybe he could "release" his eyes to the target a little quicker to take some bend off his back?