US Immigration from Dominican Republic

I have consular interview in Dominican Republic on June 1 and have been notified that the name in the passport does not match name in the ds260. I've tried to correct mistake several ways but have been unable to do so. Is this a serious mistake that can result in denial of visa?

Mother in law has a pending 130 by my husband USC. Will be sending in an adjustment of status application as well (485). She is visiting the US on her tourist visa since July and visitor status expired in January. Should I be sending in any other documentation for adjustment of status application?

How many flights or months do I have to spend in my boyfriend s country (Dominican Rep.) to prove my relationship is legitimate? I only spent 2 weeks there, going back in September. But does the weeks/months/tickets count?

After staying overseas for about 8 months as a greencard holder during Covid19, should one still apply for a Citizenship? Add any foreseeable issues with that? Asking for a close friend. After questioning her upon return, they allowed her back in. I told her I would help her apply for her citizenship. She's been a permanent resident since 2016 via marriage. Your thoughts and tips/insight please....

I just paid the immigration fee for my three stepkids who have received their visas. The A-number and IV numbers on the visa correspond with the receipt but receipt numbers are different from the original USCIS case numbers.

The problem is that there is no names connected to the case numbers to confirm anything.

I received an email stating:

Your payment was applied to the following case(s):
numbers are different from the original USCIS case numbers.

I can't get anyone on the phone at USCIS and have no idea. I am very nervous and confused. Please help.