I recently filed for CS for one child that my soon ex husband share. My concern is that he has another child that he was never ordered to pay support for. The case was dismissed. Will my amount get adjusted if the other child's mother applies for CS? If I agree to keep it a verbal agreement w/out the court will it still be CS that I am receiving from him or just gifts? I do want to keep it simple but I'm afraid that my daughter will get less.

No never do it "verbal" then he can just not pay you a penny if he has to pay the other child. It works differently in various US states as to how it is paid, if there is two separate orders, in some the first valid order is the highest paid.
Next no if there is no court order it is just gifts he is giving, not child support.

In the state of Michigan, if a father has another child, the support for second child is based on his whole earnings. They do not take into consideration if there is another case. Verbal agreements will never stand up in court. Also in Michigan if you give your child money other than the support (No matter how much) it has to be sent through the friend of the court or it is considered a gift. We send money order in the name of the mother and it would not be taken off his support. No matter what, use the friend of court so it is all documented.