Looks like pretty much all the questions are answered.

Thanks Jamie Gorton for this useful information.

I should have used word "Suspended" instead of "VOID" for your current status. ( But again, that's what USCIS rep. told me)

@ suraj2062 and @ roomrent969:
If you are in H1b and get approval for TPS, your H1b will gets suspended and will be protected by TPS. And if you change your company from A to B, follow all the steps regarding "How to move to Employer B from A on H1B visa". If you simply change from A to B and your visa petitioner is still A, you violated the H1B status and you will be out of status once TPS ends. And since, H4 is H1B dependent, he/she will be out of status as well.

@ Gorton Law
I definitely can't risk my fixed 6 yrs of H1b status and apply for TPS. But, thank you so much for your valuable information.

Conclusion: Anybody can apply for TPS but need to maintain all the requirements to come back to their original status once TPS ends. ( As Gorton mentioned, H1b can't work on two jobs, can't simply change from company B to A and work to company B without changing the H-1B Visa Petitioner at USCIS, F-1 can't work more than 20 hrs/week , F-2 and H-4 can't work at all ).

Are there any questions that needs to be addressed for the USCIS officer ?

Good luck to all.