I personally feel like you don't understand Lulu all that well, as it was already mentioned Lulu has terrible late game damage since her AP ratios don't scale well. She's got a rather slow base movement speed and is very easily caught if she over extends.

As far as your items go I cannot figure out why you've bought EM on her, your cheat sheet recommends you take Exhaust and Flash, so the passive SSR (The main reason people tend to buy this item I might add) is rendered useless. It's also taking gold away from what could be potential damage items, how often do you see another mid laner build this? Never.

There also isn't a section which details your item choices, when to build this item, when not to build it, why does it work on Lulu? What are the cons of the item?

Your intro is kind of confusing as well I don't understand how Lulu is "underestimated and overseen" if she's "overseen" then surely people don't underestimate her? It also isn't very clear that you play Lulu as an AP mid, it would also be nice to see an explanation of why you feel she is a better AP mid than a support.

Oh and lastly Runic Affinity doesn't increase Baron Buff duration.

How to use lists:

Your first vote is a downvote because firstly your guide is extremely short, secondly you give me the impression that you don't know what you're talking about. Lulu has no cons and amazing damage? No. She has good early damage and awful late damage. Her AP ratios are bad. And hint: her biggest con is that she is weak against gap closer champions. One of her biggest counterpicks (even though he's not a mid laner) is Xin Zhao.