First of all its very important which support you have! When i play Ezreal, i prefer to have a Leona, Thresh, Sona or Lulu as support! With Ezreal you should play deffensive till lvl 3, because at lvl 3 you got the spell 'q' to poke the enemys, the spell 'w' to give extra attack damage to your m8's and your spell 'e' to secure a kill or to escape!

Because of your passive, your boots and your masteries you dont need a deffensive item. If you do 'e', then you hit a 'q' you got your 'e' ready again. So you can escape every time!

Its important to stack your tear that you've muramana very fast, so use your 'q' !
Farm:
10 min ~ 80 - 90 cs
20 min ~ 180 - 190 cs
30 min ~ 260 - 300 cs min !