Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Races of Destiny as the OP did in fact express for the Forgotten Realms setting in 3.5e is an interesting book. At times may contradict however from Races of Faerun sourcebook I do believe so take it with a grain of salt if so due to bad writing. (I will need to double-check on that one as it has been a while)

But overall, I wouldn't worry too terribly much about any mechanical differences in nwn2 vs that sourcebook if at all. And how that may affect RP.

To be clear, however, Native is simply a subtype to Outsider. It really just means they reside in the setting's core prime or whatever the main place of existence to a setting, such as in Forgotten Realms that's Toril, in our setting, that's specifically the continent of Fearun, etc.

To quote:

A subtype applied only to outsiders. These creatures have mortal ancestors or a strong connection to the Material Plane and can be raised, reincarnated, or resurrected just as other living creatures can be. Creatures with this subtype are native to the Material Plane (hence the subtype’s name). Unlike true outsiders, native outsiders need to eat and sleep.

They don't generally get any crazy bonus' that the true outsiders gain such as upper and lower planer natives, etc.

I looked this up before, it has come up in the past. In lore they count as native outsiders, but in NWN2 they count as humanoids (just an engine implementation detail).

Even if they were typed as native outsiders I don't think banishment should work anyways since you are casting it on the plane the are native to.

The extraplanar type kicks in when they are not on the Material plane, which doesn't come up often in bgtscc.