I have a Canon 70-200 that I am using on the ursa mini pro and I don't know if I should be using a rail system or if the body can handle the weight of it since its metal?

The f2.8? I think it would need some support. An EF mount isn't all that strong.

The f4 would be fine without support.

I routinely see 70-200 2.8 without the tripod collar and I have not heard of any issues. You should be fine.

I use one on my Canons and have not been using supports lately. The thing I believe you should be careful of isn't normal use, carrying it around, etc, but anything that would provide a sudden shock, like dropping the camera or bumping into something. it's a heavy lens, and just about at the limit of what I'd be comfortable using without a support system of some kind.