RE: BCM943224HMS. Had a devil of a time getting this to work -- gave up on the upgrade and connected to Ethernet to grab the Yosemite download and create a USB drive to rebuild from scratch. Didn't work either.
Tried Clover Configurator as well to change to MacBookAir5,2, with no luck.
Then I tried this:
Boot Up > Clover Menu > Options > SMBIOS > Product Name : MacBookPro5,2 > Return > Return > then F4 then boot into OSX
Not a full fix as I have to do this on each reboot, but it does work repeatedly so far. If sleep mode is fixed with this + the fairly new f5.0 BIOS, I can probably live with this for now. Haven't had a screen glitch yet for 1600x900 mode (unlike Mavericks) so might be the lesser of the two evils.
Thanks again @the OP for this great tool / guide!
(EDIT: F4 may only be needed once. Tried rebooting a few times / change to MacBookAir5.2 and no F4 and still working)