Question about bottom grates on my 2 Star

If I am going to use ONLY the top shelf when cooking do I even need to put the bottom grates in?

No. But it comes in handy if the plan changes and you need to put something on the bottom grate during a cook. I always primarily use the top grate (to get everything as far from the heat source as possible) but always have the bottom grate in just in case it's needed mid cook. Yes it gets crud on it that needs to be scraped off but it's a small trade off for those instances where it's needed.

Right on thanks Scooter.