I have tweaked the numbers to align with Australian Standards.
Assuming beams and columns are modelled as frames, the stiffness modifier table is as follows:
AS3600 ETABS
Beams.......................................0.40Ig I22 = I33 = 0.35 (would use 0.40 for link beams per Australian Standards)
Columns....................................0.80Ig I22 = I33 = 0.70 (would keep columns at 1)
Walls-Uncracked.......................0.80Ig modelled as shell – f11, f22 = 0.70 (would use 0.80 for wall piers per Australian Standards)
Walls-Cracked...........................0.40Ig (would use 0.40 for wall piers per Australian Standards)
NOTE:
Walls are generally not designed for out-of-plane bending to avoid excessive longitudinal reinforcement. In this case, use a small modifier, say (0.25), for m11, m22, and m12 to avoid numerical instabilities. However, use m11, m22, and m12 = 0.80 (or 0.4) when considering out-of-plane bending in walls.
Flat Plates & Flat Slabs....0.25*Ig modelled as membrane – f11, f22, f12 = 0.25 / modelled as shell – f11, f22, f12, m11, m22, m12 = 0.25 (for both cases, fxx is not important if a rigid diaphragm is assigned)
Generally, I would try 0.60 modifiers as a middle ground for walls and assess the shear distribution in the link beams over the height, using judgement.
Following is what CSI clarifies on their website under the link:
https://web.wiki.csiamerica.com/wiki/spaces/etabs/pages/1474670/Modeling+concrete+cracked+section+properties+for+building+analysis