Darkbeer, what you've laid out there above is like a horrible game of Jenga.
Disneyland management has ignored their parking problem for a decade, and now they are in a world of hurt. To get any of the structures built they have to close the big surface lots that have 1,500+ spaces currently. But they can't spare to lose 1,500 spaces for any length of time. And once they get all the new structures open by 2021, the Resort will have dramatically higher attendance with the new hotel, Star Wars Land, and Marvel expansion all open or opening.
What a mess. It's a mess that TDA has made for themselves over the last decade, especially the revolving door of Presidents that place has. Ouimet (a great one), Grier (a real nothing), Kalogridis (a good one), Colglazier (a stuffed shirt if you ask me).
It's going to get very messy in the next few years before it gets better. I imagine the employees will be parking at Angel Stadium a whole lot in 2017 and 2018. That's if the Angels continue to want to play along.
Yes, it is that, and maybe more....
Let's see, AGW has extra spaces available currently, but for how long?
The city actually owns Angel Stadium, and rents it out, and has some control over the parking, same as the Honda Center and even the ARTIC lot. So there are some options, but then they do also have to plan for the sporting events, concerts, entertainment (like Disney on Ice and the Harlem Globetrotters) events.
The Convention Center has lost spaces due to the expansion north of the Hilton, so the city will need to "borrow" some on busy days.
So what to do??? Like you said, Jenga here we come...
If Disney can get the Pumbaa Structure started, they do have some "slack" until Star Wars Land opens. But that has become a bigger can of worms than anybody expected due to the political games being done behind the scenes in regards to the Anaheim City Council in general. (I wish I could quote someone from the "11".... something about getting an one-up on the big boy. but a lot cruder)
And it starts with the need for MORE parking for the Construction crews and equipment for both the Eastern Gateway and Marvel Land/TOT projects. And then we have Christmas Season coming, which will create the busiest (based on history) time in late December and January, needing parking for the guests and CM's (and other outside employees in the area)
There are some large businesses in the Disneyland area that would be willing to rent out their employee parking lot on weekends, but at what cost, and the need for shuttles, and limited times they are available....
So what does Disney do? Offer higher incentives for Carpooling and using public transit to CM's/employees?
Be forced to limit attendance due to parking issues? (I doubt it will happen, but it is a possibility). But you still might have a lot of locals just ed off at the parking hassles, and waits to enter a lot and find a space, and just give up and not visit....
Heck, let's look at one option... Disney getting a month to month lease on the empty lot south of the Castle Inn. The following would have to happen, a permit to build it, an environmental impact report, the build of the lot, which based on current California law requires special drainage systems to prevent run off of oils and other vehicle fluids. Then pave the lot, getting lighting and a security facility, and what do they get, maybe a couple of hundred spaces, if that many......
It is a VERY large can of worms, and should be fun to watch the fishing...