All GW FAQ's and Errata will be used. Check the GW website for these.
We will be using the INAT FAQ, with a few exceptions, as a guideline for rules not covered by GW, or where GW rules are interpreted differently by different people. Specific rulings about specific situations occurring in games will still use the TO's verdict as the final say in all matters.
Exceptions to the INAT FAQ:
1) Hive Commander rule that gives a Tyranid army +1 bonus to reserve rolls may be used even if the Tyrant is not on the table. In a similar way, Imperial Advisors (astropath, and officer of the fleet) will still grant their bonuses when not on the table.
2) When a deepstriking unit is making the initital placement of a model, before scatter is rolled, it may not be place in impassable terrain, or over enemy models. This includes Mawlocs and Monoliths. (And to avoid the immediate question, yes, spore mines may be placed on top of enemy models.)
3) If a Hive Tyrant joins a unit of Tyrant Guard, and the unit is engaged in close combat, then for purposes of the Tyrant putting attacks on the enemy unit, and the enemy unit putting attacks on the Tyrant, treat the Tyrant as an Independent Character. (IE, models can pick out the Tyrant if he is in base to base with those models, and the Tyrant must be in base to base with enemy to put attacks on the enemy unit.)
4) The Spirit Leech ability from the Doom of Malanti does not affect units embarked inside of vehicles.
5) Valkyries: To shoot at a Valkyrie, measure to any point on it's hull. Wings and Tail sections are ignored. The Valkyrie measures it's own shooting and LOS from it's weapons mounts, as normal for vehicles. Use the base of the model for assaulting the valkyrie, and models embark/disembark to the base. If the model is immobilized, use the base as it's footprint, rather than placing the model on the table.
Preferring to win a competitive hobby doesn't mean that you're a powergaming noob. Likewise showing up with an auto-losing list doesn't mean that you're a "reasonable" gamer and therefore occupy moral high ground.