familiar stacking

I have some questions about familiars and tumor familiars. And I'm just interested if it has a set way it'd be ran in PFS.

1) A wizard with a familiar take eldrich heritage for a familiar. How many familiars does he have? How would you calculate the levels if you combine them?

2) An alchemist has a tumor familiar and takes a level of wizard and gets a familiar. How many familiars does he have? How would you calculate the levels if you combine them?

3) an alchemist has tumor familiar and then takes eldrich heritage. How many familiars does he have? How would you calculate the levels if you combine them?

And now, if I have two familiars, do I get the bonuses from both of them for PFS? One would be active as the combat choice, but would the other still give me it's effects if it's on my person but not part of combat?

From this line in the familiar entry-

Levels of different classes that are entitled to familiars stack for the purpose of determining any familiar abilities that depend on the master's level.

And this on the arcane bond from the arcane bloodline

Your sorcerer levels stack with any wizard levels you possess when determining the powers of your familiar or bonded object.

You combine the levels definitely for eldritch heritage and wizard, but the alchemist tumor familiar lacks that language combining them. I would still default to the original familiar entry in the wizard section and rule that you only have one familiar and all your class levels that grant a familiar stack to determine its total power level.

And if you managed to get two famaliars somehow, with the one combat animal restriction that familiar that was your combat animal would stick around and you would only get the benefit from it. Your noncombat animals vanish and have no mechanical interaction at all.