Your list looks good - though personally I would swap out that flamer for either a plasmagun or meltagun. You've got enough anti-infantry from the bikes' own bolters for almost anything you'll face at 500 points.
Tactics-wise, I can see you've steered away (hah! pun not intended but I'm leaving it in there) from any close combat options, obviously save from Sammael himself, so use that extra speed to keep them out of combat. Don't get too worried about staying too far away for rapid fire, but do feel free to charge the last remnants of a unit to get rid of it if it's far enough away from everything else.
Deploy second if you get the chance - you want to keep your units bunched together so you can concentrate them on a small part of the enemy at a time, rather than all at once. That means your opponent will deploy in exactly the same way if he sees you doing it, but if he deploys first there's a chance he'll spread out to your advantage.
...oh, and try not to rub it in too much when your store realises in a couple months' time they should've held onto those Dark Angels bits. Nice find, my friend.