Standard forensic genetics is charecterized by its power of discrimination... Yet, for example, it can not distinguish individuals witinh a monozygotic pair. While forensic genetics is inconclusive concerning this issue, epigenetics nowadays is offering a new perspective; taking into consideration that each application has its own limitiations... So the best answer in my opinion is that they complete each other in the purpose of more resolving forensic caseworks...
Probably the epigenome might be different in case of a monozygotic pair. Therefore, a combination of both genetic and epigenetic approaches might give a more conclusive answer.
I think the answer is no. There is sufficient variation in the genome such that each individual has unique identifiers, whereas the epigenome varies even within an individual depending on the origin of the cells used for analyses..