I think a full length Ridgerest, a Light Year 20 (7"x14" stuffed), and a bulky Wally World tent will push the limits of the Ohm's internal capacity at only 2100 c.i. None of those items really lend themselves to external carry on that pack. Not to mention the addition of extra clothing.

Have you actually had all that stuff in the Ohm??? If so is there still room for 4 day's worth of food + most of your small stuff?

To me the Ohm seems out of sync with the rest of your equipment. It is not a beginner's pack.

An inflatable pad would free up some room inside the pack but it won't be nearly as rigid as the Ridgerest. But don't forget that the Ohm has its own suspension so it's not mandatory that you carry your pad rolled up like a cylinder with your gear in the middle.

If I were in your situation my next target would be the tent if your budget allows.