File LCA or H1b before 60 day grace period ends

  1. During the 60 day grace period after employment is terminated, what is the last day the candidate’s LCA can be filed ?

  2. Assume the LCA gets filed on 55th day and H1B on 65th day, is there any violation ?

  3. If the candidate files for F-1 visa on 50th day and then goes to school or keeps looking for job, it is a valid scenario?

  4. Once any employer files H1B after F1 has been filed, can the F-1 visa petition be withdrawn?