What kind of analysis can be done with differential expression of transcription factors?
Expanding my comment. 

TF usually bind in the upper region of the genes it regulates, so you could see which genes are in the region below the binding site. Perhaps there are some databases for TF. 
I found a website base on the ENCODE project with the genes regulated by each TF.You can use them for pathway or gene set enrichment analysis, but I am not aware of any specific analysis for genes regulated by a single TF. 

The histone data is harder if it was methylation I would say to look if different states of the histones are in different spatial state, but with gene expression is harder to conclude anything. Nevertheless you can check methylation studies to see if gene expression is associated with methylation changes.