...been thinking about both the necessity of all these sporting bans (and other non-sport measures) and their efficiency in bringing about the most useful end result.

If that result is, which I have to believe it should be, the removal of Putin from office and the establishment of some sort of classically liberal government, then presumably that would have to happen from within Russia—a revolution of some kind, either violent or non—. Massive economic sanctions + exclusion from all international participation (such as sports) = life becoming so desperate and shitty under Putin that the citizenry finds a way to get rid of him.

But I'm not sure how much, for instance, banning the soccer team from playing anywhere furthers that goal. Does a nuclear-armed madman really care about a WC qualifier with Sweden?

That said, obviously that has to be done on moral grounds, regardless of how effective it is.