If you assert them as fact, yes, they're inadmissible. Mostly. You could submit the affidavits as "we assert as fact that people are willing to state this, which gives us reason to believe" and yadda yadda to plead for your case to be allowed to get to discovery. The video evidence, yeah, that's effectively worthless. The wisest avenue would have been to lean onto election committees to publicize / gain access to enough information that you could use it to bolster your initial arguments - "we have this statement from the election official and full footage of the events in question, yet we do not see that these two align and it gives us reason to suspect..."
There's also the fact that in that DC case, the appeals judge told the lower judge that he fucked up and settlement was reached. I didn't look specifically into the appeals, but afaik most of them were denied similarly to the original denial.
You should still be able to FOIA more-full footage of the election day events afaik, though. You can compel the state to release more than it has thusfar (has anyone tried?)