>Does anyone else see a way to exploit this?
You already mentioned one yourself without realizing it
>If "liberal" invokes the image of an oversensitive otherkin teenager, it'll shift the public's opinion in our favor.
What you need is a meme, like the one of the hippy woman, who always gets portrayed as dump or a hypocrite.
You need a potentially viral image of a stupid looking, but associative close to tumblerism feeling teenager. This, you then make their official face and spread on pages like 9gog. Like the hippy-dreadlock-lady meme, you start with ridiculing statements that the broad public itself already condemns or a group of people like gamers, for example, already look down on. And then you let them spread it for you. To fasten this process you can either send it manually to Facebook sites with a lot of likes or you can buy 'shares' of that image on fiverr.com.
Example of what I mean:
Has never read more than 5 pages of a biology book
[insert image of extrem/retared/stupid looking tumblerite here]
Thinks mixing genes will make us all better
Doesn't know shit about economics
[insert image of extrem/retared/stupid looking tumblerite here]
"PAY EVERYONE EQUAL BECAUSE MUH FEELS"
You could do this with every group of people, whether it's tumblerites, communists or other cunts. The key is: The person who is supposed to share the image must feel like adding to his or her own value by doing so, otherwise the person will not share it. This is key, so I repeat it. The person must feel like it highers their status, their percieved intelligence/humor/sophistication, sense of reason, you name it. Therefore you must pick statements and positions that make this possible, not the ones you hate most.
After you've established the meme, you can bring in the one you really want to get out. But first you gotta establish it.
Book on the subjects:
Dawkins, The Selfish Gene