Others here can answer your leaking water heater better than I can.
Take a photo and post it so the details can be seen by experts.
I am no doubt dissecting the air-intake–drip pan too much. As Ej said, you can put a feather duster under the tank. And the product manual says you can remove the burner and use air pressure to blow out the arrestor screen.
So technically it is not necessary to elevate the tank to get a vacuum cleaner under the heater.
However recently I saw a 3 year old tank installed in laundry room where the intake screen was clogged with dryer dust. Typically people vent the clothes dryer better than to let lint clog the water heater air intake. On the other hand, that particular clogged screen could not have been cleaned with feather duster.
Fortunately for the guy, the heater was still working, but the tank rusted out around the cold inlet, and Whirlpool allowed a full replacement. And naturally the customer installed it back in the laundry room again.