hi,

May be you can use the unused addr pin as inputs if the circuit don't damage the output of addr and activates the input of P2

No. As I already said they may be used only as output.
It is because during MOVX, the strong pull-ups on all P2 pins is activated. If even pins are at "1" (configured as input) - anyway they are at strong high level. And if at this time peripheral device outputs zero then short circuit occures.

Regards,
Oleg