I have browsed through that thread....I will take a closer look at it.  As mentioned, we do use mass walls in 80-90% of our projects. Rarely do we use steel studs, however if we do we typically use external air barriers, 2-3" of ci as well as spray foam in the bays.

THe hanger question was not related to floor loading, but rather lateral loading by the basement wall (back on topic).  But I suppose your method still works. Attach to the webs. Sounds easy enough.

Our state (Iowa) heavily enforces IECC2009. All projects reviewed by the state (schools) must pass the requirements (either performance or perscriptive).  Not sure exactly what you mean by no foam in the cmu cavity.  Are you refering to inside the cmu block or the space between the cmu block and the outer wall structure?  Our insulation is always on the exterior of the cmu...

Sorry I wasn't clear on the CMU insulation method. Putting foam blocks "inside" the CMU or putting pearlite or other insulative material "inside" CMU block has long been a code loophole to increase the average R-value. Since average R-value is meaningless -- this trick is specifically listed as no longer code acceptable. Regards.

See 2009 IECC - Commercial Envelope section.

I assumed that is what you meant. We have never done that.  Always exterior insulation. Used to be 2" of xps, but changed to 2.5-3" of closed cell on the last 2 projects to hit IECC 2009.
Ill read more up on the ICF schools.  Might give it a try on an addition or something.  I have used it on 2 FEMA 361 saferooms (16" forms) for community centers, but never on schools yet.

A retaining wall is just that. Something that retains the earth. There are cantilevered retaining walls, and tied walls. The basement is one of the latter. Being designes as such, the "tie", in this case the floor diaphragm, must be in place before backfill. Other requirements you have to meet will depend somethat on the building code inspector.