Hi!
Citizens of the European Union can stay in Switzerland without employment but must have sufficient financial resources and health insurance. I think 25 000 CHF is not enough for a "B" permit. Permit "B" for an EU citizen is over one year and 25 000 CHF is less than the year subsistence minimum. I saw information about 30 000 CHF somewhere.
I don't know how it works with the "L" permit but probably different, because it is a short-term permit.
Remember also that as an EU citizen you do not need a permit for a stay of less than 3 months.
The sentences above are my opinions resulting from my reading of Swiss laws. I am not a professional. You cant send an email to the Migration Office in Zurich (Migrationsamt). They usually respond very quickly.