Tsukasa was a high - school student before the petrification. He was very strong and athletic. He had a sister who was ill. His main motivation for his actions in the Dr Stone world often related to his desire to create a world where the strong protect the weak, which was influenced by his experiences with his sister.
His sister's illness and his athletic ability are key. His sister being ill made him question the old world, and his strength gave him confidence to change things in the new world.
At the moment, there's no definite information about more Dr Stone manga. It could happen if there's enough demand and the creative team is up for it. We'll just have to wait and see.
It's hard to say for sure. The decision often depends on various factors like the popularity and sales of the original series, as well as the author's plans and the publisher's strategy.