SBF - All created things are contingent. God is said not to be contingent. That's the best argument for God in my view.
This seems too circular to be useful, as you're baking "created" into your argument. "Let's assume God, assume He created everything, then reason that, since everything else is created, it must prove an uncreated and non-contingent being, which we'll call... oh I don't know... how about 'God'."
For this argument to have any persuasive power, it would need to establish that the universe was created--or at least that it's contingent. Failing that, your second point fails because it presents only one option for non-contingency, when there are other--perhaps better--candidates for the job.
That doesn't mean it's not "among the best" arguments for God, it just shows how bad all the arguments are.