About endlinks. It's really easy. Any changes are not needed on them at all. No setting, no adjustment. I have installed them as they were from factory. And everything is fine. That understeer and oversteer question is related to sway bars. Rear sway bar from Suspension techniques manufacturer has two mounting points for endlinks. One is for "understeer" and second "oversteer". Physical explanstion is this:

Thanks to this are all RWD cars "oversteering" when you drive fast through bend and slipping...

And all FWR cars are "understeering" when you drive fast through bend and slipping

Really nice it's explained
here (I know it's for game but it's true

) or in picture below with relation to ESP

And you may change with this sway bar setting your car is reacting like more oversteering or more understeering...
Hope I have handled that with my English to not confuse you much