I've just installed KStars on a new Mac and tried to import all my profiles and settings (especially my local horizon) from linux using the following command
The biggest difference between the Linux and Mac versions is that in the Mac version, the other drivers and programs KStars needs are inside the app bundle. You need to go into the KStars preferences into the INDI tab and check the check boxes to the left for using the internal INDIServer and Internal INDI drivers. Likewise, for XPlanet, you need to check the box for Internal Xplanet. You are going to have a similar problem with Astrometry.net.