I don't think you could really have a social media aware Corbyn without loosing a lot of his effectiveness. People trust him because he is a relic from a bygone age not despite of it.
As to what he stands for: Opposing austerity is enough for the leader of opposition if it is not a election year. And even then it is worth more than all the all the focus grouped visions you tend to get usually.
I mean you can easily spend five years fixing the damage Dave from Marketing did and be not even half done.

I'm also rather fond of his People's QE. Putting the idea out there that banks get free money and you could to is the most effective attack on the household capacity I can think of on short notice.