A few changes I feel are kind of necessary to curb some of the overkill that this game system has. There's a few too many weapons, some of which are potentially very common, that amount to "I kill you on a 4+", or even "I kill you automatically". So this is an attempt to curb that.
Flamer: Targets set on fire by a flamer are extinguished on a roll of 4+, not a roll of 6. It can be assumed that military personnel will have proper training and equipment in protecting themselves from arson attacks - unconscious targets, animals or other targets that have no reasonable means to protect / counter being set on fire are extinguished on a 6 as normal.
Graviton Gun: Movement penalties from Graviton Guns apply only for the model's next turn, not for the whole game! Models whose Movement is reduced to 0 must roll 1D6 and will suffer 1 wound for each point the roll beats their Toughness by (ie: a T3 models that rolls a 5 will suffer 2 wounds). A roll of 6 will always cause at least one wound. No saves of any kind are allowed against these wounds. Flying models struck by a Graviton Gun may attempt a Cl test using the pilots Cl to regain control and avoid crashing.
Photon grenades: Effect changed to the following: Models affected by a photon grenade (after any saves) roll a D6. If the roll is greater than their current Wounds value they fall to the ground unconscious, otherwise they become confused. Unconscious models make a Willpower test on 2D6 in the Rally phase. If the roll is equal or less than their Willpower, they regain consciousness and are considered confused. These models may test to recover from confusion at the start of their next turn as normal.
Sawn-off Shotgun: This weapon is not Slow. Why would a pistol weapon be move-or-fire!?
Web gun: Web gun is now Strength 4. Roll to wound against target's Strength instead of Toughness. Models hit and wounded by a web gun are considered ensnared and must immediately pass a Cl test or suffer 1 wound. Models of Intelligence 4 or less automatically fail this Cl test. Models ensnared in a web cannot take any actions, though Psykers may still use psychic powers. Models ensnared by the web may attempt to break out at the start of their next turn by rolling 1D6 and adding their Strength. If the score is 8 or higher the model breaks free. If failed, they suffer an additional wound as the web constricts around them.
Heavy webber: The heavy webber follows the same special rules as a web gun, with the following changes: it is Strength 5, and a score of 10 or higher is required to break out.
Web anaesthetic: If a model is successfully hit by a web gun or heavy webber using web anaesthetic, the normal rules for the weapon apply. In addition, if not equipped with sealed armour, the model must pass a Willpower test or be knocked unconscious by the web. Unconscious models may not attempt to free themselves and will not recover while ensnared in the web (see Photon grenades for rules on how to regain consciousness).