TL;DR Implement follow-up notification for players who submitted reports.
First off, I have to say I like the current reporting system. It is easy to use, the categories are clear, not overly complicated by asking for too many fields to be filled out, and the comments make it easy to describe.
As a free-to-pay game, ToS runs the risk of a toxic community. It will be very important to stop this before ToS gets a reputation for negativity. Problem is; Players feel reports do nothing. I have seen people say "no point in reporting" for someone's behavior. Much of the games I encounter people feel reporting does nothing. This is regardless whether it does or doesn't, it is all about perception.
Consider implementing follow-up notifications for players who reported a player who was punished. Don't need to say which player is punished or what the punishment is, just a "A player you have reported has been reviewed and appropriately punished." Makes the community aware they are helping to do something to improve the player base.