You're right... lowering the car does not make it handle better, cos it effects the roll centre. Honda for instance go to a lot of trouble to get their roll centre to optimum by making pivot points and contol arms relatively of equal lengths. Al you are doing by lowering your car is using 50-90mm of the suspension travel, consiquently your handling is moved in the range of movement.
As for the drop off or rattle, DMS and Tein have a "helper" or Anti-rattle spring that when the car is static, it is fully compressed. On over extension it is strong enough to keep a little pressur on the main spring and prevents "banging" and rattles....
When I got my car from Japan it had (still has) HA Tein shox and springs... Lowered to 320 hub centre to guard lip. Looked horn, but impractical for my requirments (Targa Tas).
So if its asthetics you want, just throw in the springs. If you want handling, like a race car.... buy a race car. or race car suspension
Good luck guys