You shouldn't need to worry about getting hit at all as kennen, so doran's shield is pointless. Boots x3 pots should be more than enough for any kennen, as your q punishes anybody who tries to harass you in the first two levels, in addition with that autoattack/active spell by level 2, then your lightning rush should make you all but impossible to gank/harass.
Plus, the armor is pointless unless you're a solo top, as most mids will deal primarily magic damage while tops tend to deal physical, the regen is minimal, you might as well just have pots, and the health bonus means you get to tank 1 more spell or two more auto-attacks. Not very game changing as a mid. Plus it doesn't build into anything, and doesn't scale very well into mid game, so it's essentially a wasted 475 (less when you sell it).
And coca, once doesn't mean it works. And it also means brand gets to make you his bitch until level 6, even if it does work, which it shouldn't if the brand is in any way competent.