First, welcome aboard.

As for the ride qualities.............to start off that's somewhat subjective. Your idea of rough could be someone elses idea of "normal", and vice versa. If it's got a stock wheelbase it's 106", so it won't ride like something with a longer wheelbase. It could be that the rear tires are over inflated. Many will run pressures in the low 20's to smooth things out. That could also be what's causing the mild wandering in front, plus the combination of the tread pattern and road surface.

It's not uncommon for the rear coil overs to be set up with too stiff a spring. Look to see if there's an adjustment collar at the bottom of the spring, you may be able to get some relief by backing off the collar thus lengthening the spring, otherwise you may have to get some lighter rated springs. Depending on how the rear was set up they may have used spring rate to set ride height instead of multi-point mounts for the shock length. Look to see if the bracket on the axle has three holes (typically) that would allow you to adjust height without over springing.

On the front, you could have some minor bumpsteer. There are several ways to deal with that. One would be a panhard bar. This holds the axle from moving laterally which induces steering movement. If it's got shackles on both ends of the spring you can switch one end to a shackless device known as a dead perch (you only need one or the other, panhard bar or dead perch). If it's got cross steer (typically Vega) you could get a tie rod damper from someone like SoCal. If it's got side steer (typically Mustang) then you could have a designed in problem if the pivot points for the drag link aren't compatible with the locating arm (split bones, hairpins, whatever). That would take a major fix.

Then there's the issues of bind in the mountings, that would take more investigation on your part, but if you really loved the car it might be worth doing.

There's a lot of adjustability to smooth things out if the basics are right, but it probably won't ever ride like a new luxo barge.