[YuliaSnow]

How would you be able to tell if hydrazine is polar or non-polar because couldn't the lone pairs be in gauche and anti conformations (or was it trans and cis, i forgot) and so how would you tell if its one or the other? I thought that it could be non-polar because if the lone pairs were in anti conformation, there would be less strain and that makes it more stable. I haven't done chemistry in a while so this is confusing me. 

Any help would be nice.

Edit: Thanks Hunter, that made sense. I forgot there isn't a difference in electronegativity between the 2 N's.

[Hunter2]

Nitrogen has different EN to Hydrogen. So its polar doesn't matter which conformation it has. Like ammonia.

[AdiDex]

It has Sp3 hybridisation , so if a little bit distortion in symmetry it will be a polar molecule ,
And rest of the things Hunter2 have been told you.