RV Repair: Suspension?, power to weight ratio, car dolly

Question
I am a new RV owner.  I bought a 1990 27 foot Fleetwood "Flair".  I just got back from my first trip and noticed right away it didn't drive like a car.  I didn't expect it to.  What bothers me is how difficult it is to control at highway speeds.  even small cars seem to blow it off the road.  When a truck passes you it will completly leave the lane it was in.  In my opinion it's dangerous.  Is this how it's suppose to be.  If not what should I look for.  The previous owner told me he put new tires on it about five thousand miles ago, and they look new.  I tow a car dolly but it sways with it or without it.

Answer
Welcome the the "white knuckle" world of rv highway travel, one hand on the wheel and the other on the door handle.  Once you get the feel of what happens in different situations, you will learn to adapt like the rest of us.
A good steering stabilizer probably would not hurt, I put one on mine and it helps quite a bit.
It's always fun to me to follow a fellow RVer and watch the coach sway and rock, brake lights off and on.
After all, you are traveling down the road in a moving billboard and you know what wind does to them.
I have a brother in law that drives a potato chip truck for a living and you can put him in an rv in a hurricane and it does not bother him a bit.
Followup: a couple of things that I have noticed over the years that have a lot to do with the way an RV handles are: 1) weight - the heavier a coach the better and 2) power.  I gave up on Class A's because of their low weight to power ratio and most manufacturers are trying to make them as light as possible to make up for it.
My guess is that your's is sitting on a GM 454 or Ford 460 chassis.  That's the same engine they use in pickups with about a third of the weight.
I went the other direction, high power to weight ratio and when I see a wind situation coming, I just step on the gas a little and the power keeps it straight and true.  The new Ford V-10's and Chevy 8.1 liter engines are a step in the right direction.  Surprisingly, they get good gas mileage as well.  My Ford V-10 is pulling about 9000# and I never get less than 10, sometimes upwards of 14.
If you are looking for a good all around RV, look into a shorter class C with one of the bigger engines.  You might not be able to sleep an army but you aren't headed toward the ditch everytime a Moped passes in the other lane.
Good Luck!