How do I:
1) Place *dead* generic-ish NPCs with the *equipped* gear of my choice?
Make the NPCs, set their health to 0 and place whatever equipment you want them wearing into their inventories. Then drag them into the render window.
2) Set the dead guys' equipment to unplayable, so that the player can't get rich off it?
You'll need to make "new" versions of the armor/clothing for them in the CS (change the editor ID and select "yes" when asked if you want to create a new FormID) and check the "Unplayable" flag.
3) Can the corpses be set as static until the player interacts with them, or just static? Or do I just have to set them in stable positions?
You can't set them as static, but you can position them as desired.
First, place a "corpse" in the cell you want it in. Next, select the "corpse" and click the Havok button. http://cs.elderscrolls.com/constwiki/images/0/04/Tut_img_11.jpg This will cause the "corpse" to collapse. You can then hold the Ctrl & Alt buttons and select parts of the body to move around. This take a bit of practice and can get quite frustrating. press the F4 button to view the Collision Geometry and make it easier to see where to grip the body parts. Note: if you're viewing the body through another object (such as the "back" side of a wall, floor or ceiling) you won't be able to select a body part to move. Zoom in close.
4) Can normally havoked, mobile objects (such as weapons) be set as statics (so I can use them in a purely decorative fashion) through the CS? Think "the sword in the stone".
You'll have to use NifSkope for that, and you won't be able to interact with the static versions.
Open the mesh in NifSkop and expand the bhkCollisionObject node, then click on bhkRigidBody. In the Block Details window, make the following changes:
Change
Layer to OL_STATIC
Change
Collision Response? to RESPONSE_NONE
Change
Layer Copy to OL_STATIC
Change
Motion System to MO_SYS_FIXED
Change
Quality Type to MO_QUAL_FIXED
Then save the mesh under a new name and you've got your decorative static weapon.
5) Lights have a "scale" parameter, like statics etc., but it doesn't seem to affect radius or brightness. Does it do anything?
Not that I know of. The only way I know of to make a "Light" object affect a larger are is to modify the Radius setting for it in the CS.
6) Does enabling shadow-casting on statics like large rocks eat FPS badly?
That would depend in the computer.