Ok.
Sorry misread your first post, saw rice hulls not flaked rice. Hooray for coffee and glasses.
Here's a recipe for premium american lager from brewing classic styles - main differences are no crystal, and low profile hops. Cascade are going to dominate this one.
OG 1.053
FG. 1.010
IBU 20
Color 3 SRM
Alcohol 5.7% ABV
American lager yeast (californian is fine)
11.6lb american two row or six row.
1 lb flaked rice
1.25 oz hallertau hops (4.% AA) at 60 minutes.
Mash at 149F for a good 90 minutes (flaked rice takes longer than malt)
Boil for 90 minutes to reduce DMS
Ferment at 50F and lager for 4 weeks before bottling
So hops and crystal are a potential issue with your recipe, plus your process needs to ensure it squeezes what it can out of the rice.
Lagers in truth are a pita to get right, the chances of getting DMS are high, you have to do a temp rise when you are 2 points of final gravity to help the yeast consume all that buttery badness they have created. The damn DMS will still pop up at times when you think you have nailed it.
I have a great cascade smash recipe for those with excess cascade...