Once a H1B has been revoked by an employer, you cannot enter on that I-797. You would need a new I-797 to be issued in association with the application from your new employer. Your H1B is only valid as long as the I-797 is valid and the job offer exists. Your F1 visa approval and stamping also raise issues for any prior status under the last action rule.
In terms of the 30-60 day rule, are you asking about an attempt to change your status immediately after entering on the F1? If you enter on a student visa and claim that you are enrolling in a course of study, but immediately abandon that plan and seek a H1 visa, that does suggest bad faith. Have you actually been admitted to a college? Do you intend to pay tuition and attend classes?

