Would it be worth it to take a philosophy class if you’re not the best at writing?
I love to write. Unfortunately, it had very little bearing on the Philosophy courses I took in college. It wasn’t about MY philosophies; the courses were centered on other better known philosophers than me.
Logic is Philosophy that requires little writing. They really don’t like it if you come up your own system of logic. Especially if it is random.
Absolutely 
Effective undergraduate philosophy writing is analytic – understanding, identifying and picking apart the particular argument advanced. What matters is the ability to break down an argument, and assess it. So being a traditionally “good” writer in high school is not much of a predictor for success in undergrad Philosophy work.
Also it depends on the Philosophy course…Logic is a philosophy course and it is more math/proofs than anything.