Mysql – Where does MySQL store its database files on OS X

Turn on MySQL binary logging. Then you can use the mysqlbinlog command to see all data-modifying statements.

1- You should stop the mysql server (step 4) before moving the files (step 3).

2- You should stop it gracefully not using kill -9 unless needed to.

3- I think you mean start in step 5. (I edit the question).

4- You need also to check the files permissions and ownership.