As I see it, the pros to caulking are extra assurance of sealing in sewer gases, and cleanliness around the floor (if junior goes hog wild with the pee pee for instance, it doesn't find a nice hard to reach home under the toilet.) Yuck.
Negative is if the toilet leaks under the base, how would you know it? Yuck.
So could a solution in my case, assuming the floor is level, be to drill a hole in the subfloor somewhere in the area that will be covered by the toilet, so that any leak will be noticed dripping into the brickfloored old cellar? (I could even use a hole with a rubber stopper that I could remember to check periodically?
What do you think?
More toilet and subfloor questions to follow no doubt.