If I understand correctly, she will have a class (i.e. sorceress) in addition to being a vampire. So as she gains experience will her vampire skills also increase and the skill types that improve depend on her class (i.e. thief = stealthier)?
Development of vampire powers will depend on roleplaying/character development, however Valen's class may have an indirect influence based on how the player utilizes her. Class, itself, may be given some weight when determining how and what powers manifest. I am undecided on that point.
Game wise does this mean she is dual class (i.e. vampire as a kit)?
Valen's will not derive her vampire powers as part of a kit. She will be whatever class the player chooses.
Also would other newly created NPCs recognize that she is a vampire and evil?
That would depend on the author of the new
NPC. I look forward to collaboration with other mod authors such as the
Crossmod Banter Pack after the release of the Valen Expansion.