unfortunately, this is a question everyone asks and I never have an answer for.
Downsize as much as possible, etc.. Many of my clients end up in bankruptcy.
Even with your benefits, your still going to be losing a lot of income.
With a progressive disease your onset is going to be based more on when you stopped working then anything else.
Sometimes, you won't have enough proof until later (and then its an amended onset date) but other then that use the date you last worked.
If, for example, you stopped working in Nov 09, tried going back in February 10 and worked until March 2010, then you should use the november 09 as your onset date and claim the Feb-March work as an unsuccessful work attempt. Work can be an unsuccessful work attempt so long as you had not been working for at least a month and the attempt was less then 3 months long (this can be expanded up to 6 months under certain conditions). You would also need another 30 day break until you had another unsuccessful attempt (or all your attempts would need to be within a 3 month time frame - example try one job, get fired after a few days try another etc).
Doctor's or expert opinions are very helpful at getting you approved faster, but they need to be in SSA language (# of hours can sit, stand, walk per day, amount of weight can lift and how frequently, any restrictions on repetitive activities, with mental health its effect - mild, moderate, marked on concentration, pace, interaction with people etc.)
prototype states or not, the process is Initial application, reconsideration (initial app all over again) then hearing level. Initial and recon can take easily up to 6 months each and how long the wait is from the time you ask for a hearing until it occurs depends upon the hearing office your at (my area its about 15 months, places like Atlanta last I checked the hearing wait was 3+ years)