You have two attack options, with an extra elemental damage
Only one of these abilities actually improve your unarmed combat damage, the others grant you new weapons to use in place of your regular unarmed attacks. And elemental body is added on top of your regular damage.
Alright, first let's check all abilities, starting with Bone density augmentation (Core Rulebook p459), which says:
The molecular structure of your bones is altered to increase density and tensile strength. Ligaments are strengthened, and the increased bone density increases your weight a bit. Your Body attribute is increased by the bone density Rating for the purpose of damage resistance tests. You also deal Physical damage in unarmed combat, based on the Rating of the augmentation (see the Bone Density Augmentation table). Bone density augmentation is incompatible with other augmentations to the bones, including bone lacing cyberware.
Checking the table, that means (STR+2)P on your unarmed combat attacks.
Next, lets read Critical Strike (Core Rulebook p309):
This power improves a specific melee skill: either Unarmed Combat, Clubs, Blades, Astral Combat, or a particular Exotic Melee weapon skill. The specific skill is chosen when you buy the power. Increase the DV of your attacks with the selected skill by 1. Critical Strike is compatible with weapons and other adept powers. The power may be selected multiple times, each time for a different melee skill.
This means that your unarmed combat attacks are now (STR+3)P.
Razor Claws (Run Faster p113):
These claws may be used to attack an opponent using the Unarmed Combat skill. Razor claws have a DV of (STR + 1)P, AP –1.
Alright, here it says that these claws may be used using unarmed combat, but they dont improve or replace your unarmed combat. Which means you have an option, to deal your normal unarmed strike (kicks, punches, etc), or use your claws. Eitherway, both are improved by Critical Strike, so your claws would deal (STR+2)P (with -1 AP) if you decide to use them.
And finally, Elemental Body (*Street Grimoire, p170):
To activate this power, the adept must spend a Complex Action channeling the desired element. For offensive purposes, treat Elemental Body like the Elemental Strike power, with a DV of (Magic x 2)P and AP –(Magic x 0.5). For defense, anyone or thing coming into contact (melee or unarmed strike) with the adept while Elemental Body is active must resist the same DV and elemental effect as the offensive strike; fast-moving projectiles such as bullets or thrown weapons are unaffected.
As for Elemental Strike (same page):
Elemental Strike enhances the damage caused by an unarmed Killing Hands strike by channeling an elemental effect into the attack. Activating this power requires a Simple Action and the effect remains active for (Magic) Combat Turns or until the adept deactivates it with. Free Action or is rendered unconscious. While active, the chosen elemental effect wreathes the hand, foot, or other body part the adept uses to strike. Only one effect can be used at a time and can’t be combined with any other adept striking power except Killing Hands. Each elemental effect must be purchased as a separate power.
Well, this told us little, except that your hands and feet are on fire (or ice, or acid, your pick). Which means that an adept with Magic 5 would deal an additional 10P DV with -2 AP, which, depending on your strength stat, could be far superior to your other options. However, if someone strikes you, they also take this same damage (10 DV, -2 AP) without any effort on your part.
Regardless, neither said that they improve your unarmed combat damage (like Critical Strike does), but that anyone who is struck by your unarmed attacks will also take that additional elemental damage.
So you would have two attack options:
- Unarmed Strike: 11P;
- Claws: 10P, -1 AP;
If your Elemental Body is active:
- Unarmed Strike: 11P, plus elemental damage for 10P, -2 AP;
- Claws: 10P, -1 AP, plus elemental damage for 10P, -2 AP;
Since Elemental Body isn't improving either attack options, you will have to apply that damage separately, so the target's defenses would count twice. Luckily, the elemental damage has an additional AP that will make a lot of extra damage go through easily.