Total length behind the tractor may become an issue. If you are only in wide open space, shouldn't be a problem, other than that, you may have problems with a 7'. Most people tend to stay away from the 7 footers.
You may want to consider loading the tires. Since they are not currently, try everything out as is. But if you ever seem lacking in traction or stability, load them for sure. You will think that you are operating a different machine besides making the tractor ride much smoother.
The reason I didn't opt for loaded tires is that I read that you shouldn't when you have a backhoe, which I do have. I kind of figured I can always get them loaded later but wasn't sure about the backhoe. Also how does this effect finish mowing when loading the tires? Obviously a wet ground it will be an issue but that is the case loaded or unloaded.