Im comming next summer for a Rockies game. Is there a roof on the stadium in case of rain?

There are seats below the bleachers above. Rain delays happen pretty often in the summer.

No

There are seats that are exposed to the elements. I've been to one game at Coors, and it did rain. I suggest bringing a poncho just in case.

I, believe only on Club Level & Suites

No, but the concourses are covered. It almost never rains.