pushbrk

You have a point. Sounds like you did overkill on evidence. Definitely keep originals of government issued "documents" like birth and marriage certificates. Anything else you stored digitally and backed up, can be reproduced, if needed.

I can't think of a reason not to keep it all.

You have already posted the answer to your own question. See last paragraph above.

Irrelevant to the visa process. Non-issue.

Agreed. Looks like the OP wants to HAVE their cake and EAT IT TOO. They probably can, if they interview either in London or Guangzhou, no sooner than late January, but then they'll have to decide between being together soonest, and waiting for the second wedding anniversary to be together in the USA.

If you want to use a married name, do the ROM and get a new Philippines Passport with the married name. The I-130 does ask for your passport number etc. but it's fine to change it when asked again at NVC stage.

It does matter which country, so check it out at the link. Far to early to get it now. Any "expiration date" printed on the report is irrelevant to NVC or the Consulate. They care about how long since the issue date. What country ?

Exactly. The most common reason. The form is calculating properly. It's user error. 😉

One must understand that the final decision related to the affidavit of support is made based on the totality of circumstances. If the sponsor clearly does not qualify, no other circumstance matter. If the sponsor DOES clearly qualify financially, on the the considered circumstances is the relationship between the sponsor, or in this case, "joint sponsor" that causes the sponsor to be willing to act as joint sponsor. When there is no clear relationship, a Consular Officer is not going to believe the sponsor will fulfil those obligations. Same problem with "elderly" joint sponsors who are not likely to be around to fulfil those obligations. The OP needs to understand that there are practical aspects to bringing a foreign spouse to the USA. One common way of expressing this is "No money, no honey!" The time to have seriously considered these practical aspects, was very early in the relationship, long before the marriage or I-130 filing.