Yes, but you must ensure that your plagiarism rate is within a certain range. If the paper needs to be revised, you can ask Bian Xiao of China Periodical Library for help.

If the domestic conference level is not enough, it may not be found, but the power of the Internet is very strong, and if it is found to overlap with other papers, there will be problems.

It depends on how you change it. When you change a paragraph, you should change it as a whole. It's better that the order of the sentences is different, so it's basically a brand-new paragraph. Your rewritten paper may have been rewritten by others, so there are still some risks. After rewriting, it is best to check the repetition rate on the duplicate checking website such as paperpp.