Re: Help with mac install
You may find answers to Linux specific issues here.
Dragging should work. You could also establish the path (up to M2TW's main directory) and then copy it into the installer's display. But that is not essential, it will only assure that a properly linked desktop shortcut will be created.
The mod is generating it's sound files on the first start, maybe that is causing the issue when restarting? You could test if that is the case by extracting these files into the data\sound folder of the mod - it will force the mod to generate the sound files again.
The same principle applies to the map.rwm file in the data\world\maps\base directory of the game - here a simple delete of that file will force the generating of a new file.