Well from what i saw, her laning phase is actually good, you play her as if you would be Annie spamm autos, and when you have an opporunities a Cocoon. And that make an actually good laning phase, expecially if you have Kalista with you to proc her W as i said in my guide.
So yeah she have only one CC, but its level one an already long one 1,5/1,6s i think, its huge knowing like, zyra roots is 0.75 level 1 and its her only CC.
So yeah of course its not the best support in the game, just trying to show people some new picks if they are like me always searching for new ones.
The W doesnt really bother the ADC farm knowing you stay in human form all time in laning phase unless when you hit your cocoon to burst more.
And well, Leona & Miss Fortune are actually ok to face, the worst are thing like Lulu or Janna

Well i couldn't even thing of picking Elise for supp, but it is possible, if your team comp is good.
I would pick her if i have tanky engage champ like and maybe because if bot lane has a all-in champ like Thresh/Leona, because poke is very good against them. The Elise herself in laning phase, i imagine, isn't quite strong, her W will interupt with your Adcs farming and shes doesn't really have anymore CC except for E. Because of Thunderstorm masteri keystone, it would be easy to take Elise down by Leona+Mf setup. You should have time to get into spider form and try running away with E, but in this type of situation minion wave should be almost cleared by Mf CC and Leona W. Ahh anyway, Elise shouldn't even be picked in this type of meta... but anyway, nice guide :P