We don't actually know who he is. The most common identification of him as a 19 year old student seems to be a fabrication. The CPC say they don't know who he is.

The protestors had broadly the same motives as the Eastern Bloc ones. Freedom of speech and of the press, opening of the economy to more western consumer goods. Reasonable wants if you're not under economic and ideological siege by the entire capitalist world.

The only difference is that the Chinese protestors wanted to roll back some of Deng's reforms to reduce corruption and social instability. Deng Liqun, while not pro protests, saw the protests as an inevitable outcome of Deng Xiaoping's reforms