All drives have warranties. If someone has told you it hasn't, then someone needs to have their head examined. If your drive is more than 1 yr old, chances are the retail warranty has run out, but the manufacturers warranty may still be viable.
That said, Mr Rimmer ( the fool/comic relief from Red Dwarf ) has brought up possible issues with the current batch of liteon burners.
Obviously you aren't impressed with NEC either. Probably choose neither. Go with something that also gets good reviews, companies with good reviews, etc.
Concerning which to use as a reader...
I would think of it more like, which is more expensive to replace.
I'd certainly prefer to wear out a $65au/$40us DVD player than a $250au/$150us DVD writer by using it all the time for general use.
But it comes down to personal preference, and how rich you are.
Besides, the dvd player has other benefits. No atip/adip detection. Means you don't need all these copy protection features provided by all the software companies. Tis just another layer of trouble, even if they have ironed out most of the bugs.
One difference is copy protected CD's when you are copying. You need to figure out which is the better reader for these.
Everyday use though, I'd suggest use your DVD player.
Try to keep you (expensive) dvd writer in good nick by using it as little as possible.