In my opinion, the last verse means:

We rather keep to our own domain;
How well are we advised
Not to mind the frogs in the pond
And their potentates;
Spring will go; summer,
Autumn, and winter will return;
We sing resolutely and uninhibitedly
The most beautiful of songs.

To be read: we are well-advised not to rely on royal permission. Any satire that the censor can understand will deservedly be forbidden (- who said that? Mark Twain?) –

"Erdolchen": I checked several dictionaries, and they all have it. My scholarship is comprised of Wiktionary, Wikipedia, Google - often just minutes old.