1. Check local landlord tenant law.
2. All communication in writing.
3. All expenses are itemized.
4. If he does not take much, let it go. It is not worth time to fight.
My experience with the roaches is very bad. Normally they have the entire family somewhere in the walls. It is not one tenant's responsibility, it is everybody's. As a tenant, I have no problem to split exterminator bills as long as it is reasonable.
Indian does not attract roaches more than Chinese. That comment is not necessary.