I have an interesting question... how does a marriage separation affect the permit status of a spouse of an expatriated employee (EU)?

in theory it should not [certainly compared to the other aspects of the separation]. The pair would still be married and both still have EU permits.

Ok thanks. Expatriated employee is EU and the spouse isn't EU, but i guess as long as they remain married, although not living together, the spouse's right to a permit to live in Switzerland shouldn't be affected...

with the non-EU, it could cause a problem depending on which non-EU state and other factors. But the pair could, for example, hint at reconciliation should the need arise. Children involved?

Australian spouse, and yes 2 kids

The law is very clear on the spouse subject - in order for the spouse to be delivered a "dependant" permit, both persons need to be living in the same household.

See the German wording:

Cheers for your help