This question is more or less impossible to answer—it's roughly analogous to asking "Would Ronald Reagan have been elected president if Christianity had never existed?" Like, there are a lot of questions contained within the phrase "without Confucianism"—for one, would China still exist as a unified political entity? Counterfactual history is essentially impossible on such long timescales and for such vast historical phenomena.

As to your other questions, I would note for a start that Confucius did not really become persona non grata until the Cultural Revolution in 1966. For a quick introduction to the relationship between Confucius and the Chinese Communist Party, I would recommend Evan Osnos's recent New Yorker article "Confucius Comes Home."