good guide, my exact play is slightly different, but I like it. Also like your addition of the new aura item, I may have to try that on him.

I play Skarner all the time, but i build different items. But i agree with your summoner spells and masteries. Good guide.

Im the jungle you dont realy need to put a point into the fracture, generaly it is better to get the points in your exoskeleton as fracture healthgain is barely anything and your philo stone will gain your health back quickly enough.

as for runes you generaly want arounf 10 armor pen to reduce the jungle creaps down to 0 armor. if you have 6 armor pen marks and 3 attack speed marks with attack speed quintessences you can get the 10 armor pen and 15% attack speed. you dont need the movement speed quintessences because your exeoskeleton gives you the boost to catch people and they become fairly irrelevent once you get into the fight.

for summoner spells it is possible to take teleport smite this alows for you to have a major presence on the map, though you lose out on the flash ult combo. its a different way of playing and you have to be much more sneaky to grab the neccicerry person i generaly only go this way if we have another hard initiator on the team such as gallio, sona, kennen ect.

as for the guide the content is lacking slightly for new skarna player they may not have much of a clue try to expand on the mechanics of the champion and give more strategy of play.