I have a 30 amp ESC from Wattage and was wondering if I could use that with a 540 motor. Any concerns?

What about voltage and current requirements?
7.2v - 9.6v @1000 - 2000 mA range?

It will probably be o.k. but it depends on the exact motor and what load it has (e.g. what gearing and what prop). Some 540 size motors will take a lot more than 30A if you let them.

BTW when you say 1000-2000mA I believe you're thinking of battery CAPACITY (mAh) not current. Any 540 will take more than 1 to 2 amps.

Steve