I was wondering if viable playing her like a support. Using shield and stun.

Yeah, but isnt she mostly AP?
Like you would build the hourglass thing first and then deathcap and then sorcerers boots thing? lol

yes its viable, but she has more potential

As a support role (assuming that you are not taking CS) it is very hard to build the hourglass/rabadons at in early/mid game. The main problem is that both of these items build from a needlessly large rod which costs 1.6k. Saving that amount of gold at any given time on a support is increadibly hard and when you do choose to do so, you are usually doing so at the expense of your survivablity/viablity in lane (skipping on wards, stealing cs, etc)

Another problem with Morg is that her shield only protects against magic damage. While that could be interesting in certain matchups (say vs a Corki for his Q and maybe even against Tarics if you are fast enough to catch his stun), most of bot damage comes from physical damage which is not mitigated by her shield.

There's a bunch of other reasons why Morg would not be the support of choice... but to make a long story short

Janna > Morg support in almost every way as support champ

She can do it. Her shield is only helpful against the other support's harass spells (which you shouldn't underestimate -- the support's harass should account for more than half the damage early), but she has a long-duration snare and an "area" stun, and the shield's CC immunity is extremely helpful.

She's better as the AP carry, though.

She's ok, but she is banned because she's op as an ap carry, so would you really sacrifise a good mid for a ok support?

At what Elo? I've noticed in the 1300s she's rarely banned. She relies on a skill shot and her ultimate is easily negate-able with flash.

Of course a good Morgana can work around that. Though, so can a good Lux. Usually bans are saved for characters with few counters, such a Shen and Skarner.