If you mean spell VFXs, then yes. If you mean the UI, then no. You can sure get the textures and so on, but what would you do with them in NWN 1 as long as the UI isn't mod-able (which might be possible soon).
You can't import NWN 2 models into NWN 1 modules, but you can convert them from NWN2 mdb format to NWN 1 mdl format. You need to know how to use 3dmax/gmax or blender to do this. For some models it is pretty easy. You always have to scale them to 10000% of the size because what is a meter in NWN2 models is just a centimeter in NWN 1 models. For placeables you have to remove all the LODs, though they can be used in NWNEE, but not older versions of NWN. Creatures are a problem because of the granny animations NWN 2 uses. There are new plugins for blender which can also import the animations, so it may be possible to convert creatures with blender.
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You can't import NWN 2 models into NWN 1 modules, but you can convert them from NWN2 mdb format to NWN 1 mdl format. You need to know how to use 3dmax/gmax or blender to do this. For some models it is pretty easy. You always have to scale them to 10000% of the size because what is a meter in NWN2 models is just a centimeter in NWN 1 models. For placeables you have to remove all the LODs, though they can be used in NWNEE, but not older versions of NWN. Creatures are a problem because of the granny animations NWN 2 uses. There are new plugins for blender which can also import the animations, so it may be possible to convert creatures with blender.
A pity you cannot touch the UI. It needs a modernization, it's a little clunky for 2020 standards.
And yet, far, far more useable than NWN2's UI,, (with the exception of not being able to move most of what look like Windowed elements,)