Someone here recommended putting bricks under an electric water
heater, so the bottom won't rust out, I think it was.

Do many people do this?
Do you think it is important?

Is it very common for a bottom to rust out so much there are problems?
The pan around my last water heater had an inch or two of water in it
once in a great while, but it was bone dry 99% of the time. There are
small rust marks, but just on the surface.

I have height issues, so was thinking of putting in 3 or 4 tiles,
maybe a quarter inch high, like bathroom wall tiles maybe. Would that
be high enough to accomplish what bricks are for?

Should I do that.

TIA.