All 4 engined aircraft are capable of doing one thing, going in straight lines carrying load; this includes Nimrod, C130, B707, AWACS, C-17 etc
The aim of any heavy under attack is to buy time by either driving around in circles or retrograding as quickly as possible into the CAP or MEZ (Mode 4) until the 'threat' runs to bingo fuel or gets bored with whole event. The success of this depends on alot of luck on both sides.
Aim 9's will do little damage to a heavy as most of the destructive force will be directed into the engine, on the C130 and B707 this will leave the fuselage intact and the aircraft as a whole flyable. I suspect a Nimrod would not be so undamaged.
The question of Nimrod being an offensive AD aircraft is a non starter. Stand-off weapons is the future for this ageing airliner.