I'm thinking that ghouls could have penalties to Strength and Endurance (after all, their skin/muscle has been peeling off in strips, and the fellows are a tad... mushy), but are not attacked by feral ghouls (if they will be an enemy in FOOL, that is). Another idea regarding ferals is that perhaps you could recruit a single one at a time to be a temporary companion, until it dies or you dismiss it. Of course, the most obvious benefit to being a ghoul would be that your character is immune to the detrimental effects of radiation, and is in fact healed by it.
Super mutants would have penalties to Intelligence (Although it would still be possible to create an intelligent character like Marcus or the Lieutenant) Charisma, and Sneak but receive bonuses to Strength, Endurance, and Big Guns. Obviously, they would be immune to radiation (but not healed by it). Super mutants classified as enemies instead of NPCs may or may not attack you, depending on where your character's loyalties lie (I doubt they would be too amiable toward any "human-loving" brethren).
Talking deathclaws would have a penalty to Charisma (while there are talking deathclaws with charismatic personalities, such as Goris, that doesn't really matter much when people feel the urge to run to the hills after taking a single look at your not-even-a-mother-could-love-that face), and would receive bonuses to Agility, Strength, Endurance, and Unarmed. Their attacks have an increased critical hit chance, and an opponent's damage resistance provided by their armor/hide is treated as partially reduced (it's not actually reduced, an unarmed strike from a talking deathclaw just treats it as if it were). On the downside, they wouldn’t be able to equip any armor, although they could wear large, baggy articles of clothing, like how Goris always wore a large robe. Also, the effectiveness of anything involving fine motor skill is severely reduced, such as Big Guns, Small Guns, Energy Weapons, Throwing, First Aid, Doctor, Traps, etc.
I also think that FOOL should have various factions to choose from. Some could be joined regardless of race, while others are race-exclusive. You could assign certain factions to a character when you first create them, as part of your characters background, or you could join certain factions while playing, well after character creation is said and done. For example, you could create a human character who is part of the Enclave as a race-exclusive faction, but you couldn’t join them after creating a human character, since they view you as a mutant (even though you’re really 100% human) due to radiation exposure from your time in the Wastes. You could also make a human character who is part of a Vault, a super mutant who is part of the remnants of the Master’s army, etc. Of course, objectionable behavior against your faction (or rather, getting caught doing it) will cause your character to be kicked out of that faction, regardless of whether your character started out as a member of it.
What do you guys think?