I have been working myself to death trying to optimize Skyrim, I put Multibounds where there are lots of statics, and I use them on single big objects such as buildings and I put Occlusion walls on every wall I see.

Is this good or is this possibly making the engine do to many calculations?

I so far have not had any problems with Skyrim or New Vegas doing this, and I have seen positive results especially when close to a wall or looking away from objects.

I intend on doing this to all exteriors in Skyrim and New Vegas but I fear I may cause more CPU usage or even worse crashes.

Does anyone know what is best and if they can confirm it?

Also does anyone know what exactly it is I'm saving doing this? Am I saving GPU, CPU or ram usage? or all of them?

Hopefully there is some experts here on the subject.

Ought be fine, if you can use them then you probably should. Its actually making less calculations as it doesn't have to render those areas.

Its probably not worth it for vanilla as its very well optimized already theres not much to be gained by it. There are more than a few mods that could do with it though.

There is a optimization project already ongoing, Skyrim Project Optimization you might want to check it out.

I have that mod but I don't know if it uses Multibounds. I haven't looked at it in the Creation Kit, also what am I saving on by doing this? CPU, GPU or RAM usage?

Can you or anybody confirm that this is safe? I don't want to sound rude but I just need to make sure, because I use it a lot.

Here is the typical way I do things:

http://www.mediafire.com/convkey/5136/hsca72zpz14wqrezg.jpg

Its not skyrim, but its the best example I have.