Lost Vietnam passport,I-94 and B1/B2 Visa, can I go back to US in future?

You will need to reapply for your visa to return to the US. But explain everything to them. If you are timely leaving they should give another one.

If you have had the green car for two years or more you are OK. If less, then it is problematic but still workable. The only issue I see is that...

For the expenses yes - for the work - no.

Can TPS status be converted to green card

Not by virtue of the TPS itself. You have to process another avenue - marriage, employment petition, etc.

Can an F-1 student who does not pay for their next semester remain in the US and get married to a US citizen with no problems?

You can marry and file your paperwork. You should file asap to not have a problem.

I-485 part 2

Congrats to you. I think you should hire an attorney to o this. Visa waivers are tricky depending on your jurisdiction and sometimes can cause...

You can write to the USCIS and tell them how you feel, but in reality you are not sponsoring her and not responsible for her.

Does anyone has more information about the deffered action and the work permitts for August 15

No word yet as to what to do, and so no one is second guessing...........

How long it will take for the I130 & I-1485 application process ?

If you married more than two years ago, then it will be a 10 year card and it will be normal.

My school has not issued me an i20. i have a missing document that is on its way i expect

You need to find out about the I-20 before you file.