Tyre change and rim rust.

I liberally coat the inside of the rims with Agricastrol rust inhibitor. Bought a 5 litre can years ago and still some left. It's pretty effective. My other approach is stainless rims from the Devon rim co. 

... about any type of wax / oil as I could imagine it either rotting or lubricating the tyre / tube. If a rim is rusty I just wire brush it thoroughly then prime and enamel, giving it a good rest before fitting the tyre. I do make sure that the strength isn't compromised however.

Silicone lubricant as grease or spray won't harm rubber or plastic products, although oil-based will damage rubber.

Silicone grease is available in various types and is popular amongst the shooting fraternity - like me!  It's not cheap, but you can use it sparingly to spread around the inside of the rim and nipple tops.  Keep it away from anything made from wood though!

Another idea is to spray (or hand paint) a metallic paint around the inside (any colour) - or even a clear coat "varnish", like wot you should use as a top coat for all metallic paints.

Not long after I got my Dominator, I replaced the cheapo tyres.  The chrome rims were newish, fewer than 5 years old, and very rusty in the wells.  I wire brushed them, and painted with some primer with rubber in it, for elasticity.  Scroll on a good few years, and I replaced the tyres again - the paint was immaculate, but it did make the Avon RoadRiders tight on the rims, especially the rear.  I would recommend not making the paint too thick.

On another bike I am restoring which has original rims and spokes in passable condition, I have used a rotary wire brush in an electric drill to de-rust the wheel wells, and painted them with Jenolite Rust Converter.  It eats up any remaining corrosion, and leaves a dark grey plastic coating which prevents further corrosion.  While I was at it, I coated the spokes as well, as the zinc plating had come off.