Researching rebels - map garrisons and descr_rebel_faction

Ok, question for everyone. What is the relationship between the number of rebels placed on the campaign map as garrisons or otherwise found in descr_strat (beginning of the game), and the rebel factions as defined in descr_rebel_factions.txt, and their effect on rebel aggressiveness at campaign start?

Are the roaming rebel armies at the start only affected by starting rebel garrisons, or are they supplemented by the rebels from descr_rebel_factions.txt?

Do the slave faction settings have much effect - the amount of money they have, and the AI settings?

Aside from affecting unrest when the faction_creator does not own the province the rebels in descr_rebel_factions.txt are found in, what does chance do? Is it actually giving a percentage chance per turn that a group of rebels is generated?

What does "category" define, in DRF.txt?

When do the rebels as defined in DRF.txt show up, and when do "brigands" show up? Is it possible to modify brigands so they are not generic?

What happens to rebels when faction_creator is set to slave for a given province?

Thanks,

-khel

Anyone able to answer those questions? I do need to know the very same things