Does this approach give the maximum audit score?+

A smart contract must have a function against all types of possible attacks.
Smart contract must not have an update function
I will add a 2.5% tax function, which I will probably reduce to 0.5% as liquidity increases.
And if a hacker can theoretically take over the administrator rights of a smart contract, then I need a function that makes it impossible to increase the tax, that is, the tax cannot be higher than 2.5%.
The tax address cannot be changed.
Next, you need to install a function that prohibits sending tokens to the address of the smart contract.
4 administrators

  • the ability to safely waive the right to a smart contract.

So the question is, is there a function that makes it impossible to increase the tax more than the set value?
What features should I add for security?