Not necessarily. A Green Card requires that the US be your permanent home. Simply returning every 6 months is not a legal guarantee of maintaining status. If you have legitimate, short-term travel commitments, it is advisable to apply for a re-entry permit to protect your status.

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.

This is strongly discouraged. Entering the US on a visitor visa with the preconceived intent to convert to student status is considered misrepresentation and may result in a permanent bar from the United States.

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.