Once you put the new tire on a rim (hopefully a well painted rim) and fill it with a non corrosive fluid (wiper fluid), It will be years before you have to take them off for new tires unless you spin on pavement a lot. Without tubes in the tire there very well may be rusting inside but a good drill and wire brush will take care of it. I didn't want tubes just for the fact that it's a hassle to fill 11 gallons into a 12x12x26 tire with tubes.
The easiest way to fill the tubeless tire is to mount tire, seal both beads with air (50 lbs), release air and lay flat on side, break the bead open on the side the tire stem is on, fill the tire with fluid, then re-inflate sealing the bead again. That's the fastest way. I didn't dream this up, I read it on here some time ago and it worked great.
Here's something else I did to my 322 rear wheels. I drilled another air stem hole on the opposite side of the wheel so now it doesn't matter which way I have my wheels mounted wide or narrow stance, there is always an air stem available even when the weights are on.