Didn't u forgot something about lockdown and psistorm?
a good Terran palyer would scan the enemy base first, and if he saw ghosts/templars/defilers, he would just cast EMP on them, they get no energy, and he would keep always searching for more
and then, they would even make defenseive matrix on BC's
SV rocks =P
Dont ask me how to avoid that, cuz i dont know either, vbut maybe, EMP the SV first, i guess