This is what I'll say about "too much usage." When I say that I don't necessarily mean that having "too much usage" will cause some negative effect on your team. When you have too much usage on the court, though, it means you've got usage you paid for that you're not using and are likely sacrificing elsewhere as a result, most commonly in terms of efficiency but sometimes in other areas as well. The key to success in this league is generally to be as lean and efficient with the money you have as possible - to avoid paying for excess minutes and usage that you don't need at the expense of one or all of less efficient possessions (lower shooting %s, more turnovers), fewer possessions (less rebounding), or letting your opponent use their possessions more efficiently (defense, steals, blocks). The margins between teams are generally going to be small, so giving up fractional amounts in those other areas in order to have minutes and usage that aren't needed can be the difference between making the playoffs and missing them.
As a result, in my experience (and this is anecdotal evidence, not empirical evidence, so take it with as large a grain of salt as you need) teams that do a better job keeping a consistent usage level of around 100-110% on the floor will be better off than teams that fluctuate between, say, 90% and 120% (or even wider than that) depending on who's in the game.