I leave out the hardener so the plates can be cleaned off with warm water, if the plate is a good one I can harden it before drying.
To me, the thicker emulsion provides a better density because there is more thickness to the image. The other emulsion I used was very thin and did not give negatives to be printed out. I just pour the plate like collodion, drain, and set on a leveling table.
The last time I made an emulsion I did not use any hypo sensitiser and it worked fine, so I think that step can be eliminated.