@oleander Thanks, this is all really helpful!
I'm really curious about Brewer drainage. So maybe I'll take the hit and do some scouting next summer. I don't like talus, but I do realize it's a reality of off-trail hiking; gotta pay my dues.

I read a report wherein they ascended the small ridge south of Brewer Creek to a large flat area (which seems accurate to what I see on a map) and said it worked well. Only time I've ever read it mentioned. I'm wondering if that's a route to attempt. If I'm coming north in Cloud Canyon, I think I may try it just to give some solid TR feedback.
If I'm coming from Marvin Pass, I'll try the Moraine Ridge route and aim for the lake at 9700.
West side of East Creek: I read a report that said the same thing (maybe it's your friend?). I think I'll try it just to collect some TR info for others. Hard to tell from satellite images, but perhaps I'll hike the trail on the east side until the talus, then head to the creek and cross to the west side.
Thanks for your time and insight!