3) Finally, make all other factions more expansionist, like this:


//========================================
//Faction Behaviour
//This is the default behaviour of each
//faction, various in game factor will
//alter it. Rebel are always set to REBEL
//these are the available options
//also note that these are related to the
//product spreadsheet
//CATHOLIC_EXPANSIONIST_CRUSADER
//CATHOLIC_EXPANSIONIST
//CATHOLIC_NAVAL_EXPANSIONIST
//CATHOLIC_ISOLATIONIST
//CATHOLIC_TRADER
//CATHOLIC_CRUSADER_TRADER
//CATHOLIC_DEFENSIVE_CRUSADER
//CATHOLIC_DEFENSIVE
//ORTHODOX_EXPANSIONIST
//ORTHODOX_STAGNANT
//ORTHODOX_DEFENSIVE
//MUSLIM_EXPANSIONIST
//MUSLIM_PEACEFUL
//MUSLIM_DEVOUT
//POVERTY_STRICKEN
//DESPERATE_DEFENCE
//CLOSE_TO_SUPPORT_LIMIT
//POPE
//BARBARIAN_RAIDER
//REBELS

//========================================
SetBehaviour:: FN_ALMOHAD MUSLIM_EXPANSIONIST
SetBehaviour:: FN_BYZANTINE ORTHODOX_EXPANSIONIST
SetBehaviour:: FN_DANISH CATHOLIC_NAVAL_EXPANSIONIST
SetBehaviour:: FN_EGYPTIAN MUSLIM_EXPANSIONIST
SetBehaviour:: FN_ENGLISH CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_FRENCH CATHOLIC_EXPANSIONIST_CRUSADER
SetBehaviour:: FN_GERMAN_HRE CATHOLIC_EXPANSIONIST_CRUSADER
SetBehaviour:: FN_ITALIAN CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_POLISH CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_RUSSIAN ORTHODOX_EXPANSIONIST
SetBehaviour:: FN_SPANISH CATHOLIC_EXPANSIONIST_CRUSADER
SetBehaviour:: FN_TURKISH MUSLIM_EXPANSIONIST
SetBehaviour:: FN_ARAGONESE CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_BURGUNDIAN CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_GOLDEN_HORDE BARBARIAN_RAIDER
SetBehaviour:: FN_HUNGARIAN CATHOLIC_EXPANSIONIST
SetBehaviour:: FN_NOVGOROD ORTHODOX_EXPANSIONIST
SetBehaviour:: FN_PAPIST POPE
SetBehaviour:: FN_SICILIAN CATHOLIC_NAVAL_EXPANSIONIST
SetBehaviour:: FN_SWISS CATHOLIC_ISOLATIONIST


There you have it - in just 5 minutes anyone can mod their game to give themselves a much greater challenge. Just be sure to make a copy of your files before changing anything.

Cheers!