Razorbil; put your location in your profile.
the only real issue is the time it takes to charge and the possibility of "unexpected life". for me, it happens on a daily basis which is probably the result of having young kids.
as a blanket recommendation, just use the 80% charge. even if you dont plan to use more than that, if you ever do, you wont be caught with "your charge down"
your climate sounds ideal and guessing hills are an issue for you which can really kill your range. I know a PC'er who lives in your neighborhood and he deals with hills, random snowstorms (which he states used to be relatively rare but he has been hit with a few in recent years) and what not
so its like how often do you vary your schedule?
what is the longest regular trip you make?
what is the distance of longer regular trips you make?
if any of the latter 2 questions fall into the 40-60 mile range then I would LEAF it at 100%.
some people will tell you 80% but I highly doubt that charging to 100% then buzzing off at least half is worse than charging to 80% and buzzing off 75%.
best thing to do is create a driving log. write down time distance, etc of every trip you make. use your odometer and reset your trip meters daily. (dont do it for individual trips) and see what your mileage is.
most people dont judge their mileage very well and you might find some surprises