On the “nothing is permanent” theme, the quote on nibbana refers to nibbana as “unborn — unbecome — unmade — unfabricated”, in short, nibbana as “permanent”.
One may also look at the Tilakkhana, the Three Marks of Existence:
Sabba Sankhara Anicca: All conditioned things are impermanent
Sabba Sankhara Dukkha: All conditioned things are unsatisfactory
Sabba Dhamma Anatta: All dhammas are not-self
As explained
here, “conditioned things” refers to the five khandhas, or aggregates. Nibbana, being an “unconditioned”, is referred to as a “dhamma”. Notice then that Nibbana is described in the third statement (Sabba Dhamma Anatta), and not in the first statement (Sabba Sankhara Anicca). Nibbana is not-self, but Nibbana is permanent.
To wit:
So, to say that Buddhism teaches that nothing is permanent, is a statement that can be challenged.
The second statement (“there is no concept of a god” in Buddhism) is easily challenged. Now, you might say “Buddhism lacks a concept of an all-powerful entity who creates the world out of nothing”. Well, even that is not true. It’s not that Buddhism lacks such a concept. Buddhism categorically refutes such a concept, for various reasons.
In any event, the term “god” most basically refers to some sort of "super"natural entity who actually exists in a "super"natural realm. Adding additional ideas like “all-powerful” or “creator out of nothing” is interesting and perhaps conforms to Abrahamic standards, but those ideas are not essential to the “god” notion.