samsung sells the whole drive or the traverse mechanism only for repair, they don't sell subcomponents like the laser assembly... look for a barcode or qr code sticker on the drive, and you will a find a part number on it. since the DVD player is considered an audio item, the relevant part number will begin with an "A" (television parts begin with a "B"), followed by (if i remember correctly) a second letter, 7 digits, a dash, and 3 digits.
as far as the drawer mech sticking, there were some models that had a problem with the drive frame being slightly bent from stress.... one in partitcular had an easy fix, the drive stood on 3 legs, two in the front and one in the back. removing the chassis screw for the one in the back usually cured the problem of the drawer sticking.