If my H1-B gets approved, will I have to leave my current job and work for the employer applying H1 for me? What are the options

If H1B is approved, and you do not have any other eligibility for employment, and you would like to keep the H1B status, you will need to work for...

If the person is retired and did not work, the answer is NO.

Will my clock be reset, and I'll get full 6 years once I come back to US in 2018?

As long as you spend 1 year outside the US, the clock will be reset.

If the nvc haven't updated their system, is it mandatory for me to upgrade the case to from F2B to f1? As mom is citizen now

You can opt out, if you would like. You can check visa bulletin to compare the lines.

Tourist visa trying to pay back medicaid

You should be able to figure it out with the hospital.

Can the employer rescind your offer if they decide not to submit my H-1B petition?

If there is no discrimination involved, you really do not have any options here.

If one reads the law, the simple conclusion would be that yes, it should be possible to change TPS to other nonimmigrant or immigrant status. But...

Will it be problematic to renew my passport?

I really do not think it will be an issue: your dad could sign for you at that time, since you were a minor.

I751 processing time question

Do not do anything, just wait: this is my best advice for you. Your application has not been pending long enough to worry about it.

Which form do I need to fill and submit if I need to copy of my H1 petition from FOIA. And how long it takes to get the copy

I am not sure if you will be able to get a full copy of the H1B petition through FOIA since it was an employer who was filing it. However, you...