A-D) My vote is to be unique and pick what you (or your customer) like best. Who cares how other people do it?
E) Single point threadmills and 60º double angle cutters are identical, except for maybe some additional clearance for the Z direction helix angle on threadmills. You could use radiused or sharp point double angle cutters of any included angle you want, or a full radius keyseat cutter. You could use an ultra fast feedrate to give the cut a faceted effect. You could make the cut with large radii in the tool path to give the cut a wavy look. The sky is the limit.
F) French boarders are ugly.
