Very ambitious project. But why not? I've done something similar for K1, just not nearly to the same god-mode extent you're planning to do.
Prepare for an absurdly long post.
The critical hit system. When performing an attack on a character, the game engine uses a dice roll from 1-20 as the base attack roll before adding the various strength/weapon modifiers. An attack roll of 1 is an automatic miss, a roll of 20 is an automatic hit. With me so far?
Depending on the type of weapon you have, the dice numbers from 17-20 have a special significance. All weapons have a critical threat range. The double-bladed lightsaber, for example, has a threat range of 1, while an ordinary lightsaber has a threat range of 2. What this means is that for a double-bladed lightsaber, whenever the dice roll is 20, in addition to being a automatic hit, the hit is also a critical hit, dealing extra damage. How much extra damage? That depends on the critical multiplier number, which all weapons also have. In general, all weapons have an x2 critical multiplier, so they deal double damage on a critical hit. Some select weapons have an x3 critical multiplier, so they deal triple damage on a critical hit. For an ordinary lightsaber, with a critical threat range of 2, the same applies as a double-bladed lightsaber, but the extra damage will be dealt on either a roll of 19 or 20. Note that a critical hit is not the same as a automatic hit. While an ordinary lightsaber can get a critical hit on a roll of 19 or 20, the automatic hit will only occur on a roll of 20.
What about numbers 17 and 18? Currently the game has only two or three weapons that come with a critical threat range of 3, namely the disruptor pistols and rifles. That means again that a critical hit will result on a roll of 18, 19, or 20. Number 17 only comes into play when you apply a Keen upgrade onto a weapon. The Keen property doubles the critical threat range of any weapon it is applied to. So if it is applied to a double-bladed lightsaber, the threat range goes from 1 to 2, and if it is applied to an ordinary lightsaber, the threat range goes from 2 to 4, with a critical hit resulting from a roll of 17, 18, 19, or 20. Now you're probably thinking that for disruptor weapons with a critical threat of 3, applying a Keen upgrade would increase the critical threat to 6. Logical, but unfortunately wrong. Due to game mechanics, the maximum for a threat range is 4. The reason for this is due to the Critical Strike line of feats.
Master Critical Strike, if you recall, quadruples the critical threat range of the weapon used in the attack. Let's say you use an ordinary lightsaber with a Keen upgrade, resulting in a threat range of 4. Using Master Critical Strike results in a threat range of 16, meaning that a critical hit will result on any number from 5-20 (80% chance). If it were possible to have a threat range of 5 or 6, using Master Critical Strike would give a threat range of 20 and 24, respectively, meaning that it would a guaranteed chance of doing a critical hit, not very realistic, to say the least. So for practical purposes, the maximum threat range of all weapons would be 4.
Now that was long to cover simply one topic.
This would practically become a tutorial on combat mechanics. I'll edit this post and continue in a bit later.
For stacking attributes on the same item, I believe that it is not possible. The game doesn't like stacking attributes on the same item for some reason, though it has no problem stacking damages. Don't ask why. I believe that having a +10 modifier for one item is the maximum, though you could apply the effect to multiple items, such as one for the main-hand weapon, one for the off-hand weapon, one for the armor, one for the masks, etc. In that situation, it will stack properly.
For the grenades and mines, the damages they deal is governed by scripts. While what you suggested in stacking scripts is not possible, editing scripts is possible. The files you're looking for are k_sup_grenades.nss for grenades and k_trp_generic.nss for mines. Check for some scripting tutorials in the Holowan Labs, or ask if you need some help figuring out the language.
Not sure about the projectile animations.
For the modified NPCs, did you put the changed files inside the Override folder? Did you load a game before the NPCs either join your party or are spawned in the module you are in? If the NPCs are already loaded into the game, they can't be changed by using KT, though any new ones not yet spawned will have the changes. Same goes for the Handmaiden's appearance.
- Star Admiral