Buzzcook, so far you have introduced plastic explosives and bulldozers, which are absurd, but you have chosen not to address the issue of windows.
Security doors are good, if they have security frames. They are only as good as their weakest point.
The same is true of the house as a whole.
Windows, sliding doors, basement or garage access...
I have one friend whose stalker ex-husband somehow broke in via the ventilation ducting.
And yet we all are ascribing superpowers to anybody who can do a simple break-in.
Perhaps you are ascribing superpowers to the OP's home improvement budget...