Did my first order last October. I didn't do ED, but I can help answer the other stuff.
Random stuff happens from time to time, at the factory, front office, etc. that can change all of this, so take it with a grain of salt.
I ordered 10/2 and took delivery 11/25 on a loaded F31, including leather dash. It all depends on available slots and demand. F31 was obviously low demand and had plenty of allocations. When I ordered, my salesperson guaranteed 4-6 weeks at most, and he was right. I would call your dealer when orders open up and get an idea of allocations and what they think the timeframe might be, but I can't imagine the entire thing would take more than 3 months.
You can tell the dealer how you want to set up your lease when you order, but final negotiations are when the car arrives on the lot and you actually take delivery. EOY incentives and credits that are available up to that day will then be applied.
Deposit is technically non-refundable, but if it came down to it, and the car is delivered differently than ordered, it's possible to walk on the deal and get that money back. Don't count on that though. Plan on dropping $1k to secure an allocation. It does not bind you to the car. You can change your mind at time of delivery, but that deposit is gone.
Not sure about the CORP program and whether or not it applies to custom builds. You would bring that up when you take delivery.
To summarize, it should go something like this:
1. Call dealer, meet up with them and give them your build sheet
2. You give a deposit, do a credit check, fill out some forms
3. Double check the order form that they give you and make sure it's exactly as you want it (they made a mistake on mine, but I noticed it before production began so it didn't delay anything)
4. WAIT - it will feel like a million years
5. Take delivery and make sure it's what you wanted
6. Finalize lease paperwork, which is where you do all the incentives, credits, decide how you want to slice it up, finalize how many miles you want, etc. Shouldn't take more than an hour or two max.
7. Drive home in your new car
A lot of good information here for the wait, after you've placed your order:
Ultimate Guide to BMW Tracking (Order and Delivery)
http://f30.bimmerpost.com/forums/sho...d.php?t=680467