If the FISA judg(s)e knew the dossier that was given was paid for by Hillary's campaign, would they still have issued a warrant?

the answer to that question is unknown.. but highly unlikely that they would have done so

probably not

I'm not sure how the federal system works, but in most cases, a defendant's atty will dispute the validity of anything being admitted as evidence against his/her client. If it works that way w' the feds, I think that argument would have held water. Unless the judge had a personal distaste for Trump, he/she would likely have declared the Steele Dossier inadmissible.

You Cons need better information sources. It was shown in sworn testimony the FISA court know that. It was also proven under oath the investigation started before the Steele dossier.

Watch the damn hearing on C-Span for yourself.

Yes, if other independent sources confirm the contents of the dossiers. Also, the dossier was paid for by other Republicans when then Candidate Trump was running for President. If the judge was focused only one part of the dossier and there was a second independent classified source that confirmed the part the judge was focused, then what does it matter who paid for dossier?