How much trust is placed on Satoshi Nakamoto? Is the safety of bitcoin dependent on the creator of it being a trustworthy person? Or would it be safe to use even if it turned out the creator's day job was working at the NSA?
Is the safety of bitcoin dependent on the creator of it being a trustworthy person? 


No, the safety of Bitcoin is not at all dependent on the identity of its creator.

The source code is public. The paper is public.


  Or would it be safe to use even if it turned out the creator's day job was working at the NSA?


Again, the genesis of Bitcoin is unrelated to its current state or future state, except through the data of the blockchain.