Using DVD Studio Pro with later MacOS versions has become quite an adventure, but here are some things I've found:
1. Most importantly, you should obtain a copy of OS X Server for Snow Leopard, and build a virtual machine. Install Final Cut Studio on that VM in order to have a fallback position in case DVDSP completely breaks.
2. I'm currently running DVDSP on Sierra, and I of course must select button overlay colors based on position in the list, working blind.
3. When I select Build to build a disc, DVDSP sometimes freezes while trying to animate the file selection dialog box, requiring a Force Quit. (At least DVDSP returns to the same project on reload.) I've found a solution:
In Terminal, enter the following command:
defaults write -g NSAutomaticWindowAnimationsEnabled -bool false
This doesn't turn off all the animations, but it seems to have disabled the dialog box zooms that have frozen DVDSP.