If his sibling is a USC and makes over 125% of the current poverty level than yes, his sibling can sponsor you. Living in the same house is not a requirement. However, if the sponsor does live in the same house I believe they file a I-864a(this is AOS phase. I can’t remember if there is a similar document for the K-1 I-134 phase)
His parents may cosponsor as well if they meet the same requirements I stated above. You can have up to two co sponsors. His parent(s) can sponsor you if they have sponsored someone else but odds are if it has not been 10 years they are still legally responsible for the other person they sponsored. That’s something they need to look into. Is that person still in the US? Are they a USC yet? Are they still a GC holder? What visa did they use to come over? As long as they can prove that they make enough money to support their house hold (this includes the two of them, likely the person they’ve sponsored in the past, you, and any other dependents they may have) you won’t have an issue. They have to disclose if they’ve sponsored someone else in the past.
If his sibling is a USC, makes over 125% poverty level for their household then I would forget the parents and stick with the sibling. But keep in mind if his sibling has any children because they would have to make 125% poverty level for their household including you and any children they may have.
Yes
Something like this: "I filed I-129F petitioning for the same beneficiary with assigned case # YSCXXXXXXX as it was denied because my finance and I did not meet the requirement of physical visit within 2 years. We now meet this requirement, thus, I would like to file new petition for my fiance..."
Include a copy of denial letter for previous petition
