I think you have a great plan that is simple and should work just fine.
I agree that you can skip the rest at 122...I think the bugs you're using will eat the starches whether they're long or short.
I would add this suggestion: only recirculate you mash until you stop seeing bits of grain and husks; the cloudy appearance of the wort when it first starts flowing contains starchy bits that will become food for the bugs in your lambic blend. Heck, if you don't mind a few bits and pieces in your boil kettle, then don't recirculate at all! Not quite a turbid mash, but still "helpful" to the lambic bugs without adding extra steps...in fact it shortens the brew day slightly by removing a step.
Oh yeah, add rice hulls to the mash if you have not already thought of it.
I've used frozen raspberries in the past, with wonderful results. Two or three bags from your local grocer's frozen section is plenty for five gallons.
PS: I've had "extras" from wheat beer batches -- and even a "failed" Berliner Weiss -- that I've added a few drops of slumbering lambic to and ended up with terrific results -- even though the base brew was not crafted to be a lambic. And adding fruit certainly helps. I know right now many stores have some fine looking white peaches -- they might work well in a lambic.