I think that so far the best place for the FAQ is the forum.
Please don't post your question here, but start a specific thread, then I will collect questions and answers here.
I will update regularly this post and number the FAQ edition (0.1, 0.2 etc) so that they can be translated and updated also in aother languages in the specific forums (help is appreciated here).

IMPETUS FAQ - version 0.1

MOVEMENT

SCYTHED CHARIOTS
How many times can scythed chariot move?
SC cannot be disordered but they must take a Discipline Test after the second consecutive movement, like all olther troops. If the fail the test they stop (even if not disordered).

LINE RELIEF (5.10.4)
What other actions can a legionary unit perform after this manouvre?
None.

MELEE

FLANK/REAR CHARGE
Who gets the +2d6 charge bonus and when?
The +2 bonus is for the charging Unit. If the Units that charges on the flank is a supporting Unit the +2 will be added to all other modifier and the whole halved. It work like an additinal impetus bonus but also spent troops can benefit.

Can a Schiltron and Wagenburg suffer from a flank/rear charge?No. These troops don't suffer from any of the consequences of a flank/rear attack. No +2 bonus for the attacker, no disorder and they are not destroyed if they loose the melee.

A unit is hit in flank but wins the melee decisively destroying the enemy, can it pursue? If so....in what direction? Yes it can (must) pursue. The enemy is destroyed as the Unit is no longer a Unit, but fleeing men can (must) be pursued.
As for the direction the pursue is straigh ahead or in the direction of the of the fleeing Unit (even if destroyed is where disbanded men are assumed to be).

RETREAT
A unit loses a melee but can't retreat due to impassable terrain immediately behind it....what happens?
If the Unit can start a movement (maybe there are 2mm behind) it make this small retreat and much probably will be contacted by the pursuer. If already in contact then it is destroyed.

DISENGAGE
A unit is hit in rear and melee is a draw, can it leave the melee (by moving forward)?
No, beacuse the disengage is allowed only if contacted frontally.


FIRE

When you can actually fire at point blank range (< 5U)?
You use short range if you were in opportunity and the enemy charged you. This simulates the fact that you need cold blood (as well as a specific training) to wait till last moment. Only English longbowmen (troops with longobow A) can do this (fire at point blank).
If the enemy enters your ZOC to fire or to manouvre it is supposed is taking time to do that, so is more stationary in your ZOC, and you can fire at point blank