The last thingy (the one before the forgetting) is simple.
Since I suck at explaining verbally, I'll do an ASCII explanation.
Here's what the cells (a part of the gfx file, there are 16 in creature gfx) are for (Note: Player creatures only!):
| 1 2 3 4| 1: Head 2-6: Leg animation (loops back and forth)
| 5 6 7 8| 7: Body 8: Nothing
| 9101112| 9-12: Optional torso animation for weapon type n
|13141516| 13-16: Optional torso animation for weapon type n
As you can see, there can be two different wep animations in the main gfx file of a player creature. If you want more, you can do another file, that should contain ONLY the weapon animations (you CAN, of course, do more there, but we don't need anything else than wep frames).
For example, check the two .png files in the Notrium textures folder, creature0.png and creature0_1.png. The first one contains the frames 1-8 plus two sets of wep frames, and the second one contains just an additional set of wep frames.