hi LarryMal, probably the best way to pre-set certain settings is with the way that's described in http://kb.mozillazine.org/Locking_preferences for the homepage especially, also refer to https://mike.kaply.com/2012/08/29/setting-the-default-firefox-homepage-with-autoconfig/

Place a local-settings.js file in the defaults\pref folder where also the channel-prefs.js file is located to specify using mozilla.cfg.

pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0);

These functions can be used in the mozilla.cfg file:

defaultPref();	// set new default value
pref();		// set pref, allow changes in current session
lockPref();	// lock pref, disallow changes

Note that localized (complex) prefs need special treatment when you set the default value of such a pref.
Note that mozilla.cfg needs to start with a comment line (//) as this line will be skipped.
The mozilla.cfg file is evaluated as a JavaScript file with full chrome privileges and thus can contain advanced JavaScript, but this also means that any error in the file will throw an exception and prevents Firefox from starting.

• http://mike.kaply.com/2012/03/22/customizing-firefox-advanced-autoconfig-files/