Thanks too much bro! Everything clear now. After a lot of research and code analysis I think I have been able to understand how it works.
I suppose that address exclusion happens to have more tokens available for holders, after transfer fee. Contract address receive liquidity fee, and the creator address has no privileges over the rest of holders, although it receives _rTotal amount at first:
It is very common that when creating an ERC20 the owner of the same receives all the supply of the token. In this case you receive it in the form of rTotal. Remember that it is nothing more than an equivalence with respect to a MAX. But for practical purposes it is the same as transferring the tTotal at the beginning.