regions are different than video standards (NTSC/PAL) they are kind of a gatekeeper. Papers Please. If the DVD has the correct region key the player plays the DVD. And yes all you need to do is leave all the boxes checked.
As for PAL, most European countries have DVD players that play back NTSC disc, the need for conversion is not that big of a deal anymore (not true for PAL in US though). Making a PAL version of a DVD is a complete reauthoring, all the assets need to be converted. PAL and NTSC cannot live on the same disc.