Can I enter the U.S. on F-1 after filing a sibling-sponsorship petition?

Hello! I’m the wife; my husband is trying to get an F-1 visa, and I’ll accompany him on F-2.

My older brother is a U.S. citizen, so I’m considering filing a sibling sponsorship, but I’ve been holding off out of concern it could create restrictions for the student visa. Honestly, going on a student visa is also meant to help us get settled and eventually change status within the U.S. (F-2 → work permit → EB-3 processed domestically). My questions are:

1. If a sibling sponsorship is already filed, and then a student visa is issued —

Will I need to check the box indicating I have family in the U.S.? I’m not sure if the system cross-references whether a sibling sponsorship has been filed, or whether it just happens not to come up if we’re lucky.

Even though the sibling sponsorship would take over 15 years to reach our turn, I’d like to file it as soon as possible just in case. Could filing this now (with me, on F-2, as the principal applicant) affect my husband’s F-1 visa next year?

2. If the student visa is rejected, does that affect the sibling sponsorship?

Given that we’re an older couple, there’s a non-zero chance the student visa could be rejected, and I’ve heard that ESTA also becomes harder to get after a rejection — would this affect the sibling sponsorship down the line?

3. Can a domestic change of status happen while a sibling sponsorship is pending?

Assuming F-1 is granted while the sibling sponsorship is pending, if I (the F-2 dependent and principal beneficiary of the sibling sponsorship) request a change of status and work under EB-3 — is that a viable scenario?

Or would I need to cancel the sibling sponsorship after entering the U.S.?

I’d really, really appreciate any answers you can give.