Oddball, no that's not the case. The depth of the bed is measured from the apex of the edge, where ever that might be within the edge profile.
As far as edges go, if you decide to go with a more vintage, or rounded edge profile, my advice would be to only do that on the batter side - keep the snare side edge sharp-ish. This gives a good balance of a vintage sound with improved sensitivity.
Beds are personal preference. Of all of the beds I cut, my go-to is a fairly deep, flat bed with steep transitions. I keep it just between the lugs (I'm a 8-lugger guy). I've tried the shallow and wide (beyond the lugs), and that works as well. I'm not a big fan of the more narrow beds with long transitions. They yield a lot of body, but less snare response. Just my experience.
