Is extrapolating from the past really useful if the Chinese government has been completely replaced in a civil war, which was followed by the massive changes of the cultural revolution?

Likewise, is Germany a dangerous country right now because "we" have started 100% of world wars within the last century? Honestly, I wouldn't even trust our military to capture Luxembourg right now... (probably for the better!)

This applies to all aspects of China's development, of course, not just their military.

Perhaps they were not, though they were so dominant that they had no security fears and had other levers of power.

Contemporary China has militarily threatened or even had conflicts with most of their neighbors, including Japan, The Philippines, Vietnam, India, and Taiwan, and also the U.S. Communist China fought a war with Russia in the mid-20th century, invaded S. Korea (with the N. Koreans' assent), and invaded and annexed Tibet. They have built-military and quasi- military bases in Sri Lanka (not sure of the status of that one), Pakistan, and Djibouti. They've built infrastructure supporting potential military logistics throughout Asia.

The Chinese government's talking point is in the comment above: China does not interfere in other countries affairs and they seek a 'peaceful rise', citing their history as if President Xi restricts himself to what was done in the Qing, Ming or prior dynasties centuries ago. Almost all warmongers in history, or the ones with any sense, have made the same claims about peace; look up some German propaganda from the 1930s.