I'd rather my fan leaves get mass amounts of light than my buds...I don't run sog but if I did I would trim most fans after about 20-25 days of flower and then again after 40-45 days of flower. That way your buds are getting the most light that they can get.
It all depends on the strain, anything with strong indica or northern lights heritage for example, tends to grow into a single cola naturally. When trying to SOG a Sour Diesel though, a good bit of pruning and canopy management would be needed and a lot more work. Strain selection is very important to a SOG grow.
Kushes have a goodly amount of sativa in them, so frankly, no. They also are renowned for being fairly poor yielders overall, thats why its often crossed with something else, to boost the yields.