Diana is one of my favorite mid lane players,altho' i dont play mid that often but its from my main mid laners. Bad early game ,but while she ll hit 6 with a early gank she can snowball and ganks lanes easily. YOU MUST LAND Q OFC.
Warwick is such a useless champion that works only at broze X,he has good sustain but hard clear wave (top). As for a jungler is usefull only if your team mates are winning the lane,so you can 'gank' with your e even before hitting lvl 6.