1st-just max one skill, there is no point in putting one point in each to keep balanced, i did it when i was lv 4...
2nd-lyandris rylais and gunblade suck on kat, get dfg zhonyas and void instead.
3rd-why get the armor in the defense tree?you will probably lane with a magic damage champion, scarificing your executioner mastery for that is stupidity...