Fair. Density is the only one that’s going to have enough flexibility to do anything meaningful. None of it those properties, including density, will have any effect on your LinearVelocity movement, so you’ll need to revert. If you do go for density, just be wary of how that will cause your characters to interact with other aspects in your game. And you’ll still have to do a little bit of math and coding if you intend on having a wide range of speeds, albeit not as much.
You’ll still have to manage the wall stickiness as a separate issue, which was the bulk of my response.
This (Releasing Character Physics Controllers) wasn’t a feature when I originally wrote the module, but it looks promising from what little I’ve read so far. It may have some of the answers you’re looking for.