I'd imagine most of the boards have discussed this ad naseum, but I understand your concern and will summarize and expound. Please note that I'm being general and not specifically describing your situation.
You've posted on this before, I'm referencing for historical purposes.
http://www.6mt.net/forum/viewtopic.php?t=13185
The performance tires put onto sports cars, like the G35/350Z, are going to be much more susceptible to abnormal tire wear from all sorts of conditions. If something is marginally out of whack, the soft rubber will show relatively quickly as compared to the tires on, say, a Toyota Camry. Frankly, you're lucky if you're getting over 18-20k (miles) on a set of the stocker Michelin Pilot Sports; if you don't like that fact (which it is a fact), get harder-rubber tires (and less grippy by measure) and accept the results. The Pilots are one of the best summer tires out there, but they trade treadlife for absolute street-legal grip. In many regards, they are a race tire with a tread design.
Tire noise is mostly caused by uneven tread depth oriented to the rolling direction; i.e., the leading edge of the tread in the direction of rotation is higher or lower than the trailing edge. The in/out difference (towards or away from the center of the tread) is irrelevant in tire noise - UNLESS the treadblock is completely gone - but then all rules are thrown out the window.
For argument's sake, tire noise is also caused by harmonics; if the tread blocks are large or are all the same size, a harmonic can form which translates to more sound/noise. Careful inspection of the tread on almost any modern tire will show that the size of each treadblock is different from the neighbouring blocks; typically the size gradually increases and decreases around the circumference. This is not useful here, but perhaps interesting to note.
That all said, here's the deal.
First: Feathering/cupping is not caused by camber. Exclusive of other alignment issues, camber wear is an even wearing of the inside or outside treadblocks. There is no cupping or feathering, no excess tire noise (until the treadblock is gone, but that's a different question). Camber can dramatically increase the impact toe/balance/suspension problems have on tire wear, but does not cause these problems independently.
If you were to look at a tire that had no abnormal wearing aside from camber wear, it would have a perfectly smooth section on the primary wear side of the tread and a full and normal treadblock on the remainder of the tire. I used to get this a LOT with my Neon ACR, I ran -2.5 degrees front camber on high performance tires for long straight-line miles. I don't have pics, but I have extreme cases where the inside block had worn completely away to the point of being near-polished and the outside looked practically new.
On both the G and the 350Z, the rear wheels exhibit noticable negative camber, if I were to guess I'd put it at about -1 degree. The front is effectively zero camber. The camber in the rear will help keep the car straight under power, limiting the tendency of the rear end to want to pass the front end under hard acceleration (i.e., the tendency to want to do donuts) or acceleration in a corner.
Second: This kind of problem could also be the result of an assembly problem in the suspension or a damaged/worn bushing, NVH (Noise/Vibration/Harshness) insulator or similar. That's hard to find, but a dealer or a reputable shop could go over the entire subsection of the suspension and check each mounting, bushing, bracket and bolt for proper installation and adjustment/torque.
Third, and related to above, it could be caused by a worn/failed suspension component. Most specifically, you could look at the strut on the feathered side and check to see if it is leaking fluid. Although hard to check, you could also verify that the car feels equally stiff on both front corners by trying to bounce the suspension when your body.
NOTE, *IF* you do this, don't press/bounce the fender, press/bounce the top of the strut tower.
Fourth, it can also be caused by improper tire balancing, and this is much cheaper/easier to check. Bring the car to a good and reputable tire shop (or, if you trust them, your dealer), have them pull the wheel and check the balance.
Failing to find a problem in those areas, you're once again looking at alignment, and most likely toe.
In a "proper" alignment, all tire wear (cupping, feathering, camber wear) should be nearly perfectly mirror identical on the tires in the same position (front to front, or rear to rear). In an abnormal alignment, wear can become uneven side-to-side. In my link above, I mentioned that feathering/cupping is a sign of toe adjustment being out of whack.
In any of the above cases, don't let the fact that it's on the right front isolate you to that side of the car - the problem could be on the opposite side but translating to a tracking problem on the tire-afflicted side (with the possible exception of tire balance). Do ensure that the car is fully checked if possible.
So far as your notes about changes to the suspension dynamics, there are a lot of things that can impact the alignment of a car. Alignment will slowly change over time just with the heat cycles of day/night, summer/winter. The suspension doesn't warm up/cool down at the same rate in all places, and this can lead to "heat creep".
Driving will impact alignment - you have 3500lbs of car and an uneven surface. Your alignment will very slowly work out of true over time just from normal use without any dramatic event.
Hard hits, like potholes, rocks or (gasp) curbing will also affect alignment.
Normal wear to the suspension will cause alignment changes. Bushings wear, allowing more movement than designed, bolts loosen, metal bends. This is all slow impact, and shouldn't be the case on a 2 year old car, but all of note.
As a side note, the driver plays a role in tire wear in a way that most people don't consider. Again, referring to my Neon ACR, the camber would change by -0.2 degrees and toe by about +0.1 degrees when I sat in the driver's seat. These are small numbers (and I'm a small guy, 150lbs), but in an autocross environment can make a huge difference. For a normal passenger car it's a bit extreme, but I would get my Neon aligned with either me sitting in the seat or ~150lbs in the driver seat.
Hope this was useful, it was certainly long.
K-
Once again . . . . Tire Feathering question ** Pictures **
