My experience with towing three different trailers.
If you have sway bars and your trailer is perfectly on the same plane as your tow vehicle, (balanced perfectly), you should have no problem with sway. Possibly a bit when a tractor trailer passes you at 70 MPH, but if you see him coming and just hold the wheel tighter you'll have no problem.
Don't worry about a blow out. With tandem wheels you won't even notice it. One time doing sixty, I heard a loud bang and didn't even know what caused it until I looked in the mirror and saw that I was leaving a trail of shredded rubber behind me
Guy