Is it possible to switch Idols during battle. If so could I say have my rip idol on just for rip and shred on for shred, and corrupter on for mangle? Sorry if this is a stupid question.
I don't believe you can swap idols, but even if you could you would be subject to a GCD every time you did. So it's counterproductive. Generally speaking I believe the Rip idol is your best bet overall, with some very specialized ArP setups benefiting from the badge Shred idol more.
This has been looked at many times over at ElitistJerks. Everytime you switch idols, it resets your swing timer which means on average you lose half a white hit each time you switch. Thats a decent chunk of damage lost for a fairly limited return. If you are idol switching twice in 20secs or so (to rip idol and back to shred say) then that is a white attack lost every 20secs = 5% loss in white damage or about 1.5-2% overall loss in DPS (assuming about 1/3 white damage). It is hard to see the idol switch being able to make up for that.