jerome1204

The Ds-260 is the valid for 1 year.  I would wait to send the documents for about a month or two.  Depending how fast you get interviews after CC. 

If there is any doubt you should make it as straight forward as possible and use a joint sponsor. They would also fill in form I-864 for their income, I-864A is used for combining income with a householder. For example my father in law was the joint sponsor for my application and his wife my mother in law used I-864A.

Approval of your paperwork at the NVC does not guarantee approval of it at the embassy.
 
Like you we submitted similar evidence because my wife had been out of the US for 14 years, on the day of my interview the officer asked me did my wife have a job already lined up in the US before we moved. I said no because we were unsure of the exact place we would be living. My application was put on hold pending my wife having a firm job offer, we had just assumed that my joint sponsor (wife's parents) income was more than enough on it's own and I questioned the officer regarding it, he said the US government does not chase sponsors for money just because they have a signed an I-864. Luckily I had a small pension that was going to continue when I got to the US and I had not included it as income, so once I proved that it would continue and that it exceeded minimum poverty guidelines I was approved within a couple of weeks.
 
The wording is "intent to domicile" and whilst I cannot say it is true for all applications I can state that I am aware of two other forum members from Ireland who have had a similar issue within the last six months, Dublin embassy requiring the returning US citizen to have a job offer before the petition is approved. I have not really kept too close an eye on this section of the forum so I don't know if this is happening elsewhere with other forum members in different counties.
 
Best of luck with your interview. 

Incorrect, the OP has stated the source of that income will not continue when they return to the US.  Therefore, it cannot be counted in terms of meeting sponsorship requirements.

I can tell you what I submitted. I have been out of US for 10 years between Canada and Europe. My case was approved at NVC and I am waiting for interview now.
 
I sent statements from a US bank account that I have maintained.
 
statements from US student loans that I have maintained. 
 
Evidence  that I am still registered to vote by absentee ballot. (From two previous elections I had emails)
 
i also included emails I have sent inquiring about transferring my children’s school and what do I need to register etc.
 
I also included an affidavit written by my mother that we will be living in her house until we are able to settle by ourselves. This took the place of a lease/home rental agreement since I am not there to sign anything. 
 
All of this was detailed in a cover letter similar to the sample someone suggested above.
 
 
 
 
 
 
 
 

Yes. Assets can be used. They must be at least 3x the required income level (or income level gap if using income too).
The CO makes a public charge decision based on the totality of the circumstances (not just minimums, so there is no way to know exactly what income/asset level will satisfy them).