Basically ive played ez for a long time now and come to realise that ap is so much better then ad, wit the marks you can use mag pen or straight ap, i dont get mystic shot till level 13, the w and e ability are basically a nuke when playing ap so go give it a try,
you might not agree with my mastiers and moves per level but i very rarely go bad with ez due to this build,

Ezreal was born with the gift of magic flowing through his veins. Ezreal, however, was also born with a much stronger sense of wanderlust. Put into school to become a skilled techmaturgist, Ezreal quickly became bored with magical studies. By the time the boy genius was eight years old, he had fully mapped out the underground tunnels of Piltover. The quality of his work was so great that the government of Piltover purchased his maps and salaried his services as Piltover's Grandmaster Explorer. This sealed the deal on Ezreal's path in life - he would eschew the arcane arts in favor of archaeology. Since then, countless of Ezreal's adventures have been written about as romanticized stories.

One of Ezreal's latest adventures, however, has brought him face-to-face with his other legacy - his latent magical power. While exploring the pyramids of Shurima Desert, Ezreal uncovered an amulet of incredible power. Aside from the sheer size of the amulet (it was made for a being easily twice Ezreal's size), it allows the wielder to control and shape magical energy - provided a source of magic is in the vicinity. This allowed Ezreal to tap into his natural talent for magic without having to put any serious effort into it - a big win for the Prodigal Explorer. The drawback is that for some unknown reason, the amulet is attuned with summoning magic. Without warning, Ezreal may find himself acting as a champion for, as he puts it, ''a summoner hell-bent on resolving some irrelevant world-shattering League conflict.'' Still, Ezreal feels being summoned into a Field of Justice on occasion is a small price to pay.

''There's little time to study musty tomes when you're busy crawling around where the musty tomes originally came from.'' Such is Ezreal's credo.

In describing how to play a character is hard, all people play in their on different style, Me for example am a very aggressive player and prefer to aim for the kills, I play ap ez due to being be able to nuke people early with my ap runes, Ez may be squishy but he is a very heavy harrasor from range, If you play your cards right and time your e ability right you cant e and w to due quite a large amount of damage, in saying this for those that prefer sitting back as ap heroes this still may work but you also need to be wary that the w ability only hits the nearest target so you need to be aggressive in some forms to do large amounts of damage or you can just harass with your w,

To be honest im unsure why people play ad ez, Yes i understand that his passive creats up to 50% attack speed but in all honesty i find that useless, 2 of his abilities stack of ad where as all 4 stack ap, in my experiances as ap ezreal i have found it quite ez to take on a ad ez due to the fact i can nuke him in the time he can get some basic attacks of,
Yes some people play ad ez well but in saying that most ad ezreals are loads of ****, i very rarely see an ap ez and it makes my day when i see one and the different styles they play them in,

Mystic shot or the Q ability is great harassment for AD ez, Ap scales for all abilities best for the W and E ability and them 2 abilities them self are a large enough nuke combined with ulti to kill a champion.