Paduppa

The sooner you file, the sooner you can proceed with the process. You can always delay the process, but speeding it up is much harder.

1) It is a factor (not reason for refusal alone), actually. See current FAM: https://fam.state.gov/FAM/09FAM/09FAM030208.html#M302_8_2_B_2
 
2) It's no longer proposed...it is a final rule now set to go into effect on a given date. But yes, important point that it does not impact DOS decisions at this time.
 
More specifically, it impacts DHS decisions, not DOS decisions.
 
Who knows what will actually happen, but that's my prediction as well.
 
As for the new form, I'm assuming that's to correspond with the (new form) I-944 as well.

Retirement portfolio of over $100,000 and she would agree to the following to liquidate her retirement income if she needed to according to I 864 instructions:
 
Only assets that can be converted into cash within one year and without considerable hardship or financial loss to the owner may be included. The owner of the asset must include a description of the asset, proof of ownership, and the basis for the owner’s claim of its net cash value. 
 
and your main sponsor has no income at all?   He is the main sponsor and yes,  the embassy can judge you will become a public charge/  they have done it many times as noted in past posts/ they will not see he is on medicaid or any other assistance but they will see he doesn't file taxes 
 

File now as it’s going to take a year. In the meantime, the sponsor gets a job and come NVC time will have proof of being able to sponsor you. 

Youd need to file the I130 before Oct 15th at midnight ie. Your package would need to be postmarked Oct 14th for the rule to not apply to you.

Tourist visas usually don't count for DCF purposes, but the USCIS field office there would be the ones to ask. 

He must have been a legal resident of Thailand for at least 6 months to file DCF. Time in country on Thai tourist visa has nothing to do with DCF timing. If he were a legal resident he would have a different type of visa which they would accept in a DCF case. 
He can call or write the duty officer at the U S consulate in BKK to confirm the info I gave. If he wants to do it in person he can. The consulate office is in the high rise across the street from the embassy visa section. 

It might be possible, but it depends on the embassy. I just recently completed DCF in Mexico on a tourist visa. I had been living in Mexico full time since 2014 so I had lots of evidence (rental agreement, IRS tax returns showing my address in Mexico, US bank account history showing consistent transactions in Mexico). I included this evidence and a letter explaining my situation with my I-130 and it was approved.