As stated above, tongue weight is the key. Get it right, and the trip will be pleasant. You can almost forget the trailer is behind you. Get it wrong, and bad things can happen, up to and including the whole rig being wadded up on the side of the road.
Usually, sway side to side = not enough tongue weight. Can also be a sign of a low tire. Bucking for and aft = too much tongue weight, but can also be a sign of a loose hitch. Don't be surprised if you have to stop and adjust the load to get it right. At the first sign of trouble, stop and fix it. Too often I see people towing obviously miss-loaded trailers. Don't do it. It's dangerous. Even after loading trailers for 25 years, from a few hundred pounds to over 10K, I still get it wrong occasionally.
Stop and check the trailer and load about 30 minutes after leaving. The load will probably have shifted. Furniture is a pain to load. It will move around. Those straps you thought were tight probably aren't anymore.
Tires that are too hot to touch are a sign to slow down. Even 5 MPH can make the difference between changing a tire on the side of the road, and making the destination with no problems.
Don't be in a hurry. People are going to cut you off and do all kinds of stupid things to get in front of you. Just let them. They will pull out in front of you. Be prepared for it. Acceleration will suck, the brakes will too. Plan ahead, and as they say at autocross events, look ahead.