The holy Elf - is that Maria (Realms of Bondage) - you're referring to??
If so, I basically just reused some of the art for RoB and updated the character a bit. I didn't really think much about it.
As for the witch. Yes, in EC1 and 2 she was a different character from Zaria in RoB. They are not related.
Sure, there will be a little more story for RoB - maybe some backstory or side quest. Probably later this year, in the winter sometime :)