Let say I have FOs in a coordinated order. Can I declare a Flashpulse (techincal weapon = WIP) with 1, and a BS attack with the rest?
Yes, Flash Pulse is still used with the BS Attack skill, you just use WIP instead of BS due to the technical weapon trait. You can even combine with Forward Observe, Surprise Shot, or any skill with the BS Attack label as of the latest FAQ: Q) Are Skills with the BS Attack label considered to be BS Attacks or other Skills when declaring a Coordinated Order? For example, could a Coordinated Order be made where one of the members declares Surprise Shot, another Forward Observer and a third troop shoot with a rifle? A) They are considered to be BS Attacks, so can be combined in a Coordinated Order.