Re David Peak bypass: That is actually the official route, although in the watershed indeed. Switchbacks down a little (2-3 short switchbacks?), long descending traverse left over old rockfall, close under the steep face of David, up the bushy valley to the col. Also has the best hope of water between a tarn north of the East Lion and Magnesia. Also not far down to Enchantment if water is a priority. Over is shorter, less elevation, better views but the descent can be unpleasant with big packs on and there is worse exposure. Not crazy in the least as you saw, but it's there.
And yes, it's often done as a long hard day hike! It's great.
Some hikers that we met warned us that bypass via watershed is illegal. We have not seen anyone - and we met about a dozen hikers on the way, who was going to complete it in one day... I had also entertained the idea before the hike, but when I saw those verticals past the Lions, I changed my mind. It could be possible with bypasses though.