H Visa

 Once an I-140 is approved and held for 180 days, the priority date is locked, and the applicant can extend an H-1B infinitely with any employer. To bridge a gap between roles, filing for a B-1 visa with an explicit intent of job hunting is a suggested strategy, rather than switching to an F-1 unless it represents a logical career progression.

A standard practice is to include a notarized letter inside the new H-1B petition package. The letter should explicitly state that if the H-1B is approved with status, the pending B-2 should be withdrawn; otherwise, B-2 processing should continue. 

While some arguments can be made that status continues as long as a full salary is paid, the safest preventative approach is to calculate the 60-day grace period starting from the day physical work stops.

Yes. An H-4 visa appointment can be scheduled and processed regardless of the specific expiration date on your current H-1B stamp, provided your underlying H-1B status is maintained.

No. The "90-day rule" is a misconception; USCIS always evaluates the intent behind your entry. Entering with the intention to change status can be viewed as misrepresentation. It is generally safer to process your visa stamp outside the US.

Due to immigration uncertainty, it is advisable to plan only one step ahead. If you pursue a PhD with CPT, select a flexible program where CPT is not rigidly bound to an immediate start. If your employment is with a multinational company, explore L-1 visa options, as they offer distinct benefits, including automatic work authorization for spouses.