Is it a body shift type coil overs? It seems not that type but just the spring height adjustment only. If that's the case then lowering that much I think is not recommended even though it seems possible by the available thread to lower the spring perch. The reason is because even if the spring perch can be that lower, the damper body & piston it self stay at the same height, hence you will be compressing the damper too much, making it work abnormally/too hard. If just having lowering spring perch then maximum lowering maybe just around 3cm. If have body shift, then you can also lower the piston damper inside the damper body hence you can maintain the same stroke for the dampers, then you can lower more.
No body shift, springs tighten max to get lowest setting.......lolno body shift. Have to adjust spring preload to lowered.
depend on spring rate and damping rate. very keras , jump jump....
Okay so will I get lower and better adjustment with these?
Yes, more adjustment can be done with this set. However how low it can go better check before buying.
you get too low = hard dampening setting=less comfort. Pls note....hehehe
Well, personal preference. Probably want more performance......you get too low = hard dampening setting=less comfort. Pls note....hehehe
Or else tyre worn out in no time.
Also, how many of you are still keeping your first car? 
