I think many of us can empathize with your "pain". I know what you mean about P-cars as well, brilliant cars, great looking, great performers, etc. However, I do think you are right that there just are "Porsche guys" and those who are not. Some basic thoughts and suggestions on the rest of your situation:
- Coming from an M3, despite the great performance of a stock and modded 335i I don't think you will be satisfied with the 335i, just from a feel and driving perception POV.
- Some dealers will be getting some markups on the M3 for some time. It is not going to last long though.
- Folks have begun dropping off of lists already, and once we have pricing and dealers start calling folks to ante up and place an order, many more will drop off.
- I think even though BMW is offering you a short term lease it is probably not be short enough to get you from your current M3, into the 335i and then into E92 M3 within the time frame that you can actually get to your place in line and an allocation.
- Despite how good/flexible/etc. the offers seem from either BMW NA and or your dealer don't forget it is their job to make as much $ on you as they can, period.
- You should strongly consider another dealer (and it does not have to be huge one) in a place further from you in your state or even in a nearby state. Many dealers have a strict no over MSRP policy and some will have much shorter lists than others. Your "leg work" could pay off getting you a car much sooner than you think.
- My last thought is just buy a real cheapie for about 9 months, my strong suspicion is that about six months after first deliveries (about 9 months from now) you will be able to walk into a dealer place your order and basically have an instant allocation. My opinion here might be a bit aggressive in terms of what is possible but based on history, the last M3 launch, the improved state of the competition and BMWs stated goal of selling 100,000 M3 over the E9X model lifespan, the opinion is justified. I know it would not be fun driving the cheapie for 9 months but you would feel great when selling it for near what you paid for it.
Hope this helps, at least a bit.