The rims don't sound too radical, the smaller diameter tyres are helpful when you make the track wider.

Did you get a wheel alignment after the suspension work? Did you get the tyres after the wheel alignment? Swapping the fronts to the backs is always a good idea, but don't do it until after you have a wheel alignment.(If you actually haven't had any alignment)

Tramlining is always hard to get away from, trucks leave tracks going up inclines because their drive tyres are pushing harder in those places. Take note of where your car gets darty, if it happens in both lanes going up, down or along the flat, I would suspect your car. If it happens in the slow lanes going uphill only, that's the road, you can't do much about it other than try & let your car stay in the one track.

What size tyres were you using before? If you can be bothered, you can give the speedo a tune up, but it should still read higher than what you are actually doing as your current tyres are roughly 10% smaller than original.