#1 - You can only find the mated faces from mate (not vice-versa) by getting the Mate2::MateEntity::Reference.
#2 - You can add the angle mate and change its value which will rotate your component.
I would also suggest you different approach of changing the mates value instead of EditMate2. Please check this topic: https://forum.solidworks.com/message/341157#341157
Application Engineer at Intercad
Tel: +61 2 9454 4444
Thank you, I will try this!