Rules clarfication on Double tap

Double Tap (Combat)

You can make rapid small arm attacks to increase the effectiveness of your attacks.

Prerequisite(s): Weapon Focus (small arms), proficiency with small arms.

Benefit(s): As a standard action, you can take a single attack action to make a double-tap attack with a small arm. This attack gains a +1 bonus to the attack roll, and your bonus to damage from Weapon Specialization is equal to your character level (rather than half your character level). The small arm used cannot have the blast, explode, flexible line, line, unwieldy, or wide line AR weapon special properties, or any other property that allows it to attack multiple targets or an area in a single attack. This attack cannot benefit from the boost, guided, or variant boost AR weapon special properties, or any other ability or effect that is a move action and alters the effect of your attack or damage. This expends ammunition equal to two attack rolls, and if you cannot expend that ammunition, you cannot use this ability.

Weapon Specialization (Combat) states that Benefit: Choose one weapon type (small arms, longarms, heavy weapons, etc.). You gain specialization in that weapon type, which means you add your character level to damage with the selected weapon type, or half your character level for small arms or operative melee weapons. You can never have specialization in grenades. And

Versatile Specialization states that Benefit: You gain specialization in all weapons with which you are proficient that can be selected with Weapon Specialization.

Also Deadly Aim (Combat) states Benefit: When you take the attack or full attack action with weapons (including a Solarian’s Solar Manifestation, but not Spells or other special abilities of any kind), you can take a –2 penalty to your attack rolls. If you do, those attacks deal additional damage equal to half your base attack bonus (minimum 1).

My question is how much damage does one do when they use Weapon Specialization. Double tap have soldier levels and Deadly aim does the damage from soldier levels stack with weapon Specialization and double tap And deadly aim

Example {7 Level soldier} with a small arm pistol doing D6 damage with weapon (Weapon Specialization) Deadly Aim And Double tap D6 + 7 with (double tap)+[deadly aim] D6+{7 Character Level} + (7 Weapon Specialization) + <7 Double Tap> +[3 Deadly Aim]

so my Damage would be D6 + 7+ 3 + 7 = D6 + 17 as a 7th Level Soldier or am I totally off in my math

Also is it worth for a soldier to take Versatile Specialization as soldiers are proficient in all weapon types at the start of the game and with Weapon Specialization it covers Versatile Specialization