NEA doesn't give you all the undead traits; that would be a pointless ability (we'd just change the monster's type to undead if we wanted it to work that way).

Basically, if an effect specifically says, "this works this way on living creatures, and this other way on undead," then treat the NEA creature as if it were undead, otherwise, treat it as living.

"Undead are immune to X, Y, Z" is not the same as "this works this way on living creatures, and this other way on undead."

So a dhampir is still affected by charm person because that spell doesn't say "it affects humanoids like X, but affects undead like Y."

Unfortunately, we don't have the option of rewording every single effect in all books in the game to clarify corner cases of how they interact with NEA. GMs will have to use common sense on how to parse the two core elements of NEA, which are, in order:

* The creature is alive (and therefore, unless otherwise specified, is affected as if it were a living creature), but
* If an effect specifies that it does one thing to living creatures and a different thing to undead creatures, the creature with NEA is affected as if it were undead.