Robert_Charlton - 8:28 am on Sep 25, 2013 (gmt 0)
bill - A quick note that the problems some people in Europe report with NTSC formatted DVDs might have as much to do with the encoding and workflow of sources along the way as with NTSC by itself. NTSC appears to be by far the best choice if you go with just one release format.
Assuming you're starting with material shot in a "hi-def" digital codec, you're going to want to edit everything in an intermediate codec like Apple Pro-Res, Avid DNxHD, etc, in the highest resolution possible... and then do separate exports for the web and for each DVD format. It can get very complicated, though, if you're mixing sources.
Depending on the complexity of your DVD programming (menus, subtitles, languages, etc), you could choose to author the DVD in both NTSC and in PAL versions, or just in NTSC.
I see that you are planning PAL for the Chinese release version. Conceivably, you could add other language tracks and titles to the (Chinese) PAL version... thus creating PAL disks for Europe. I've never looked into what might be involved in that. If imagery were different for China, of course, that approach might not work.
From research online, it appears overwhelmingly likely that a well-authored NTSC DVD will play in PAL territory, but not the other way around. I didn't even look into SECAM.