Huh, I see. That's another thing I wasn't sure about, but from what you say and what canon says, it looks like Issei really is going to inherit. ...Yeah, that's definitely going to come up sometime. I don't have any icons of him in his robes either, but we ignore the clothes in icons all the time, that shouldn't matter.

Yeah, his father is... well, there's a reason he only gets mentioned early in the game when everything's comic relief. Issei's brother isn't much different - from what I can tell, his two expressions are |D and ^_^. Issei's pretty much the only one who's srs business all the time.

I think a primer would be definitely helpful! I know there have been times when I've thought 'fffff, Issei would so know about this and all I have to go on is Wikipedia', and I often end up desperately Googling something so that I don't feel like I'm messing it up completely.