I just want to see if I'm interpreting this correctly. Since Forward Observe is a BS Attack it does benefit from fireteam bonus birst to BS attacks? The fact that it uses Willpower is only relevant in the case that it cannot benefit for the bonus to BS for 5 man or pure 4 orl 5 man teams? And on a semi related note, since it is a BS Attack I assume it can be declared as an ARO while other members shoot without leaving the Fireteam?
Forward Observer is a Technical Weapon so cannot benefit from Fireteam Bonuses. While it is treated as a BS Attack, Forward Observer is a separate skill, so cannot be combined with the Common Skill BS Attack in a Fireteam/Coordinated Order.
Forward Observer literally says BS attack under it in the wiki. And if I look lower I see the technical weapon tag that is not in this image. And apparently that has rules too. Ignore me.
It has the BS Attack label, which means it will be affected by rules that modify BS Attacks. However it is a separate skill to BS Attack. The Trooper is declaring "Forward Observer" as their ARO. Hacking Programs have an exception that allows each member to declare a different Hacking Skill, but I can't find any similar exception for BS Attack and Forward Observer.
That is not what the rules say. Page 167 says it also applies to Throwing weapons as well as BS Weapons while ruling out technical weapons. Page 170 of the rules states that it's "+1B BS Attack" in the fireteam chart. Page 170 then continues in the text with the following: Since it is a five-member Fireteam Core, they will all get the Fireteam Size Bonuses for 2, 3, 4, and 5 members. Additionally, since all members have ‘(Morat)’ after their name, they also get the Fireteam Composition Bonuses for 3, 4, and 5 members. In summary, all the members of such a Fireteam add the following Bonuses to any MODs shown on their Unit Profile: ◼ •A +1B to their BS Attacks. ◼ •The Sixth Sense Special Skill. ◼ •A +3 MOD to their Discovery Rolls. ◼ •A +3 MOD to their BS Attack Rolls. Bolded for emphasis. Page 171 continues with: Another example of a five-member Fireteam Core. In this case, all its members will gain the Fireteam Size Bonuses for 2, 3, 4, and 5 members. However, as the Fireteam is not made up entirely by Troopers from the same Unit or with ‘(Morat)’ after their name, they will not get any Fireteam Composition Bonuses. In summary, all the members of such a Fireteam get the following Bonuses: ◼ • A +1B to their BS Attacks. ◼ •The Sixth Sense Special Skill. ◼ •A +1 to their BS Attack Rolls. Bolded again for emphasis.
EDIT Forward observer is a technical weapon. It can benefit from Triangulated Fire but not from fireteam bonuses.