Well, if you look at Sleep Cell's car(read his Member's Ride thread), you can see what is possible. 'slepnav6' has a slammed sedan, that he raised slightly after putting on a set of 18x9 +23/24 wheels. The Wheel Fitment Thread has alot of various setups posted, so you can get an idea of what can be done with 17" and 18" setups of various widths/offsets.
I would say 3+" would be enough to slam the sedan, but then you run in to possible fitment issues with the wheels you may want to run. Not to mention fender rolling/pulling, rear tab relocation, possible issues with the front strut tower hitting.
I can't remember the Member's name that had the 8th Gen V6 wheels on his DEP sedan(the pics are on V6P in the 6th Gen sedan pics thread), but he has about a 2" drop. Thos wheels will not look too big at all.
You won't have fitment issues with those wheels, and you may even want to add spacers(I think he added 10mm ones) just so that the wheels are sitting flush with the fenders.
At your age(and no offence intended, I am not too far behind), and your current ridealongs, you may want to consider a more moderate drop rather than slamming the car. Ride comfort is definately sacrificed the lower you go.