How accurate does a door rough-in need to be?
The reason for a rough opening is so that it CAN be rough in dimensions. Your opening should be no problem. Rough openings are made larger to accommodate headers and floors than out of level, adjacent studs that may be out of plumb, framing lumber that has thickness variations, openings that are slightly out of square and maybe some other things I've not thought of.  

BTW, the jack studs are vertical so the proper term to describe their closeness to vertical is "plumb" and not level. The term "level" is used to describe things that are properly horizontal.