I render to DVD+RW discs all the time. I usually burn to these as I am checking my work prior to the final DVD. I have not had any problems re-using the DVD+RW disc for other projects.
Finalize is used when you're making a data disk, from what I understand. You can rewrite to a RW several times, but when you "finalize" the disk...you close it and burn the index so that it can be read on regular players.
But yeah, I think that's only a concern with data disks.
Also, I burn all my dvd's to DVD+RW because it plays in every player for some reason. DVD+R rarely plays anywhere and we don't have a healthy stock of DVD-R...so DVD+RW it is.
This is using a new sony dual-layer drive. DVD-R/+R, DVD-RW/+RW
+RW at a bit rate of around 7.5 works in all players. +R works about 50% of the time with no rhyme or reason as to why...and -R works about as well as +RW.