As stated above, don't peg efficiency on what gear you are in. Rather use whatever gear that puts you in the 4500 to 5500 rpm zone, at whatever speed you choose to travel.
As mentioned above, a windscreen gained me about 10% on range on the highway.
Since, at 41K miles on a 2013 Empulse, my SOC gauge will jump to zero from as much as 50%, I reset my trip meter each time I do a charge. I usually ride mixed riding (surface streets and freeway) and count on 60 miles of range.
Given what I know about lithium batteries (not much!), I'd be wary of forcing the discharge level by repeatedly turning the bike off, waiting, and eking out a few more miles, at least on any kind of frequent basis. Might harm the pack over time.