Explaning Cis & trans isomers through VSEPR
Answered my own bonus question (I believe): In case anybody was interested,

Trans seems to be favoured due to the methyl group on either side of a Cis bond repelling eachother (due to to both the methyl groups wanting to retain their tetrahedral structure, hydrogens are repelling one another and hence distorting things), and hence the trans is more energetically favourable.