You need to specify all Pokémon except fire types to the exceptions= variable. You only need to put the first forms, this script always ignores the evolved species
The exceptions= variable only removes pokémon possibilities, if them can't be in an egg (like the Mewtwo and the evo Salamance), then them are ignored.
I didn't understand you second question.
If you wish to made a choice between pokémon types, you need some customizations, tell me than I can do for you, is easy for me.