Does your son want to go to 4-year college?

UMD requires precalculus.

Community College will generally require taking precalculus in college, so avoiding HS math will lead to trouble.

If you really want to minimize math, take 2 -Year Algebra 2 so it's less intense and he can focus on other classes/activities.

Nope, state law is that they have to study math every year of high school, regardless of level.

My child wants to take geometry this summer and use it as one of his 4 required math credits so that he does not need to take one senior year.

Would this be okay? He is finishing up algebra that he took his freshman year.