Packing the tent loose inside is not a good idea. Fine if it never rains or you never get dew or the floor never gets dirty. If the weather is that good why even bother with a tent? If you pack a wet tent loose in the bag you will get everything wet and filfthy. It is a good idea to split the tent into 1) poles and pegs (they can go lashed to the side outside the pack), 2) fly, and 3) tent body. You may want to also put the fly on the outside in a long narrow stuff sack. I just put poles in the outside pocket rubber banded togther. But you want to protect the fly from getting tears, so it should be in a bag. The body of the tent can go inside the pack. Also, once you remove the poles, you may be able to use a shorter bag for tent and fly that will pack much better.

Consider getting a compression bag for the sleeping bag. I also use a compression sack for my clothing. Get light weight compression sacks- REI makes some very light ones, as does Granite Gear.

I think your pack has enough square inches in volume. You just need to utilize the space better. You may have to purchase some different sized stuff sacks that nest together better than what you currently have.

On the other hand, by the time you do all that, you may be better off getting either a smaller tent or sleeping bag. Where are you going to backpack? Do you really need a full blown tent? What about a tarp or hammock?