Your maxima is awesome

Lowering your ride will definitely make the ride quality a bit harsher depending on the springs that you choose and how thin you go on the profile of your tires, I am lowered on S-Tech which is the biggest drop you do and do noticed the ride quality is much less and I am running 235/50/17, I stayed with the regular profile of the tire which still allows for some comfort on the ride mind you I have fantastic steering control due to the lowering springs so I love the handling and gave up some of the comfort. If you are concerned about your ride quality may I suggest you go with EiBach spring they will give you a mild drop and still keep most of your ride quality. Don't forget you also have to change your struts, the stock ones will not last if you lower your ride the lower you go the faster the stock strut will blow out on you. So for the nice drop and good handling may I suggest you look at the EiBach springs and Illuminas which are adjustable for ride stiffness or go with KYB AGX which are a bit less money and also adjustable and least expensive struts would be KYB GR2's ... Sorry for being a bit long winded but I am trying to make sure you have all the information to help make your decision.
I love the drop that I have a full 2.2" on the front and 1.9" on the rear, I don't have to drive a lot of other people in my car (most of the time it's just me) so a bit less ride quality versing the additional control and handling was an easy decision.

it could help. but it will not completely diminish the vibration. if you figure it out, let us know.

lower it please. but the wheels look good imo

The 20's look nice. With the drop on the Megan Springs, you won't need anything else. You'll need to rent spring compressors from Auto Zone or your local parts store to get the job done. The ride will be a little stiffer and you won't be able to do much about the highway shake since it unfortunately comes with bigger wheels. So yes that is normal. You should be able to find a how-to on swapping out the springs by searching on here. I haven't seen one in a while though, but I know they're out there. Good Luck!

Yep, just got back early this morning. Back to work tommorrow.

It really is not all that complicated, they pop out pretty easy and as for the spraying you can have all four done in about an hour, I was just explaining the steps for the best result and trying to let you know that the nightshades paint is a lot runnier than regular spray paints ... you can do this!!!

Not bad. I think I may have went by you yesterday or one similar to yours.

LOL man i dont know why i do that! but ya thanks for the love she need it...im about to put up more pics later today....but ya her rims are good as they are, and her color is on of a kind. its actually a slate gray/silver...and i JUST got one of thos maxima.org decals to put on her, seing as this site makes me love my car more lol...but ya i have been EVERYWHERE, 130,000 miles but runs like it had only 50,000