I know this is a somewhat older post but could you use click in there for FoL? Something like

Code:
/startattack
/console Sound_EnableSFX 0
/castrandom Crusader Strike, Divine Storm, Judgement of Light, hammer of wrath, divine plea, exorcism,
/click folbutton
/run UIErrorsFrame:Clear()
/console Sound_EnableSFX 1

FoL macro
/stopcasting
/cast [target=xxxxxx] Flash of light
Pretty sure you need the comma at the end of random for it to fall thru correct?