I'm not selling Boris products...but I will try to answer this :-)
Graffiti is a titler. Borisfx is a compositor. Boris Red is both.
When I was on media100, I had Red. For a while I had graffiti and Borisfx, but I became frustrated that some features that I wanted to use were in one of the products, and others were in the other. I got Red....best move I made.
I am not trying to get you to spend extra money, I have no financial interest in Borisfx, but if you get Red, you will be blown away by the integration with media100. It also doesn't hurt that Borisfx owns media100. To be able to browse your media100 bin directly inside Red was awesome. Also, Red is a standalone (It is both, works in and out of media100). My workflow would be to set up everything in media100 and Red, then save that and open the Red engine.....why ???? Because I got better use of my ram, and a much faster preview and workflow.
I know that I probably haven't answered completely your question, maybe not at all, but I am offering up free advice. Graffiti will do some cool titling. Fx will give you creative power for fx....Red will do both and open up media100 to become a powerful editor and compositor.