So, I;m just about to wrap up one of the interiors for my mod and I'm wanting to ensure smooth paths for NPCs through out the place...

Are these pathgrids too complex???

http://img717.imageshack.us/i/pathgridexample.png
http://img130.imageshack.us/i/pathgridexample2.png

Should I get rid of some of the paths between nodes? I just want to ensure everyone can smoothly flow through the rooms. If I am able to do what I want, there will be 6-10 NPCs in this cell alone at any moment.

For that many NPCs, you might even want to add more. NPCs will stand on the nodes when they wander, which may limit or make awkward the paths of moving NPCs.

That said, even if your interior was just for one or two NPCs, you could still afford more nodes and/or connections if it was important to you that NPCs look natural wandering around. It is true that more nodes and connections add slightly to CPU load, but I would think most would find that preferable to all the NPCs walking in unnatural patterns.

Yeah, that's nothing. Add more nodes. Vanilla interiors have more than that. Mine have a lot more and there is no noticeable impact on performance. Interiors are small and cramped, so they can bear the slight processing overhead and require a bit of finessing to make actor movements appear natural.

You don't really have to worry about performance as it relates to path nodes except in exterior worldspaces where there are literally hundreds of nodes active. The number of connections is probably more important than the number of nodes in any case since it increases the number of decisions the actor has to make at each node.