I have had my best results with a no boil BW that I pitched a 2 qt lacto starter (fermented in the high 90's for @ 10 days) into the primary that was cooled to just under 100 degrees or so. I let that ferment around the high 90's for 40-46 hrs. I then quickly cooled the beer down and added my vial of german ale yeast to finish things off. When I kegged it, the sourness was mild and not was I was hoping for with pitching so much lacto. Well, 3 mos later I just took a taste and the beer is considerably more sour and becoming fairly sharply acidic (just what I wanted). I plan on letting this one age till early spring then carb up high and schwill away! Meanwhile, I have since made another 15 gallons to age til summer (5 gallons got 7# apricots, and the other 10 are with the WY Berliner blend so we will have to wait and see how that one goes).
Back to your question - I do not think all of steps are necesssary to make a good berliner. You could either sour your no boil wort with a handful of grains for several days, then pitch your ale yeast to finish things off, although the pH might be too low for your yeast to do much. In this case, try adding the grain to half the batch for souring and boil and ferment the other half regularly with ale yeast, then blend the two for packaging.
But I do think your best bet is to use a good healthy lacto starter at at least a 4:1 ratio with your yeast in the fermenter. I know that Midwest supplies still has of the WY berliner weisse blend which is mostly lacto and a small amount of german ale yeast and touch of brett. I have heard this strain takes about 6 mos to fully develop (most likely due to the brett though).
Cheers to the berliner!
-brewinhard
