1) if i choose an action and a another as modifier (es: carrion worm orange ability + charge) can i choose the order, or i must always do the action first and the modifier later?

2) If i am engaged from the flank/behind, i need to resolve a reform before being able to attack right?

3) when a single unit die, i must remove it from the posterior tray right? Can i choose which one? Can i do it from different trays?

1) Left dial action. Then right dial action. One thing to note is that an armor icon triggers immediately on reveal.

2) You can attack, but you get no rerolls from ranks. You use the threat of whatever side is facing your target, not you front edge’s threat. Rank discipline does not get around this.

3)unless somehow specified otherwise and I don’t think anything does: The player who owns/controls the unit never gets to choose how wounds or damage is allocated. It is always your opponent even if you caused those wounds

7 hours ago, Church14 said:

One thing to note is that an armor icon triggers immediately on reveal.

Whoops, did not know that! thank you!

Oh another thing, if my opponent has a stun token, can i remove it before the dials are revealed, before dices are thrown, or whenever i want?

For Stun tokens, you decide upon their usage after they declare they are going to activate the unit and have revealed their dial, but before they take their action.

Thank you!