you don't change the spring rate with coilovers, you change the spring seat height, so the spring isn't more compressed when you alter the ride height
I know how coilovers work, you can order different spring rate for different setup's - drivers prefernce, driver/telemerty input sugesting greater/lesser spring rates
Yes, ride height is adjustable, but you can, on the better spec'd coilover sets adjust daming bound/rebound ect....
Look on the Ohlins www site for example, or any good coilover manurfacturer for that !
Correct!! You can purchase varying spring rates for coilover suspension. To suit driving style and particular setups for varying track conditions. Not just coilovers either. Pretty much any suspension configuration can be customised with spring rates.
While the might not be the correct part for the TDI, the rates are only going to be minimally different.
I did a VR6 conversion into a Mk2 Golf from a Passat. Cut a coil out the passat vr6 springs, and fitted them to my Mk2 Golf bodies. That was perfectly safe and i never had any issues.
I would say they will be fine, however, they arent correct, so might only 99.9% as effective as they should have. You will only have issues with springs snapping from very poor quality components, of which Eibach Sportlines arent.