Yea, I agree. Something like Box Selection would be better LMB imho :) If you have a twitter account, make sure you tweet your suggestion with the #b3defaults hash tag, so people can see it :)
You need to add a subsurf modifier to view this but the "Apply Modifier To Editing Cage" isnt open to Python, AFAIK, so you can't set a hotkey for it. You can set up the other display options in the subsurf via hot keys though, so maybe that will be enough? You can add a subsurf modifier quickly and change its levels by…