tubless tire or not, rimgaurd or not. i simply prefer tubes in all my tires.
as far as corrosion, calc (err i forget full technical name) = something like salt water. that is the stuff that is corrosive and rust rims, to rusting out the valve core out (were ya put air in / check for air pressure)
there are better pressure check gauges out there for tractors, that can handle fluids better, without getting all gunked up.