Sounds like you have it. A photo would help. If you have the front restored to it's proper height, you probably don't need to go above 1000 lb bars.
Concerning your tank, looking at your floor plan, I'll bet your freshwater tank is pretty close to your axles and the tongue weight added by a full tank is minimal. If you are worried about it, calculate it by taking the distance from your tank to the axles, dividing by the distance of the tongue to your axles, and multiplying that by the weight of your full tank. That'll give you a good estimate.
The only thing I would add is that even with the correct setup, the wind is going to push you. That's not necessarily sway. Sway can happen even without wind. You are pulling a tall box with a lot of surface area. If a wind gust pushes you and your trailer together or if your trailer returns to track afterward, then it was just the wind. That doesn't mean it's any less of a disconcerting feeling. When it's windy, you have a few options:
1. Slow down.
2. Get off the highway and travel the back roads instead.
3. Pull off the road and wait it out. I know this isn't always an option.
4. Add some weight (i.e. fill your tank) to lower your center of gravity.
After getting a some miles towing your rig, you'll learn what's normal and what isn't. It's good that you are concerned with getting your set up correct. Good luck and let us know how your camping trip goes.