I'm more of a tinkerer, but thanks for the vote of confidence. For handling, you're probably at optimal height. I don't know if going lower is going to help anything. It'll look better, but I seriously doubt it would corner better. People always say that lowering helps because of the lower center of gravity. But what they never take into account is that when you lower, you're now sitting in the middle of your suspension travel while static. So whatever suspension arc Nissan designed is now somewhat compromised because you're starting at some point in the middle of it before you ever hit that bump. And when you re-align the car at the lower ride height, you've again changed the design some. Factory alignment specs are designed for factory height. The reason they go out of spec when you lower is that the suspension parts are in their travel. So when you align to factory specs at a lower height, you've slightly changed how the suspension works.
Don't know if it matters much at all, but everyone who has lowered their car has changed the design of their suspension travel. I think the only way to really know what a good ride height is would be to test it. I believe you go to the track? Other than that, we're all just guessing. Sometimes changes don't do what you think they should. A good friend had a drag Supra back in the day, it ran 8's. He ran in a pro class, so they were all looking for the last couple of hundredths of a second. He spent a lot of time messing with the suspension with different alignment settings and heights. The final alignment and height settings were way different than he anticipated, but for his setup, it was the fastest launch.
My car is set up purely for looks. It handles well, but my ride height, camber, and offset were chosen because it looks good, not because it corners fastest. I don't think you'll bottom out by going lower. I've only bottomed out a couple of times on BC's, they've designed the shock travel with the spring height in mind. Just make sure that when you lower on your rears, you adjust the shock body accordingly. I didn't do that when I first installed, and that was one of the times I bottomed out. Right now, my car is so low that I don't think I can bottom out the suspension. I bottom out when my catalytic converter hits the ground
Now it's down to a finger and a half. Maybe there was some settling ???
I can see how everyone itches to get lower, but it probably will handle better all raised up like this.
My friends stock GTR is not slammed, & that's likely the reason. Maybe resident suspension guru Shadow can chime in.