hi Kurt,
I'm in the sunny state also , Gympie , and Ive recently got a corky bark ( I've posted it,
http://forum.bonsaitalk.com/showthread.php?t=20169 ,
I've chopped the living hell out of it and re-potted at the end of august . the tree has come back with a vengeance!
what i would suggest is re-pot it and try to remove some of the heat from the balcony tiles , IE couple of besser blocks and a plank get it of the tiles .
Stuart
mrwally1954