Can one replace a tubeless tire with a tube?
All tubeless compatible rims can run tubes - that is how you deal with a puncture in on the track. 

As far as tires, you can go with any tire that is the correct size for the rim. If you get a tubeless-ready tire, its possible to run a tube and then go back to tubeless using a sealant like slime or Stan's, and they are much lighter than a tubed tire.