Proposed Modified Rules for Horus Heresy / WH40k 7th Edition

I thought it would be fun to play with the Horus Hersey/WH40k 7th Edition rules to combine some of the better ideas from Shadow War Armageddon/WH40k 2nd Edition and 8th Edition. I particularly like the idea of using more modifiers and fewer "all or nothing" rules. But I would also like any changes to work with the current unit/weapon profiles and points costs (it won't be perfect, but at least be close enough for friendly games). So here are some draft thoughts:

Agreed Rules:

Blast Markers:
For direct fire: Roll to hit as normal. If hit, place the template on the closest visible model in the target unit, as per normal rules for casualty removal. If miss, roll for scatter with artillery dice and scatter dice.
OR: Can use the standard rules (place the blast anywhere in the unit and automatically roll for scatter subtracting BS.
Indirect fire (barrage) stays the same as current if there is no line of sight. If there is line of sight, you can choose to fire directly, as above.

Not Agreed (Concepts and Ideas Only):

Movement:

Running: Move d3 x 2 (no more 1" runs!)


Shooting:

To-Hit Modifiers:
6 always hits and 1 always misses

Range:
First quartile of weapon range: +1
Fourth quartile of weapon range: -1
(?) Up to 25% beyond maximum range: -2
(For example, bolter gets +1 at 1" - 6" range and -1 at 18" - 24" and -2 at 24" - 30")


Cover:
Soft cover, rocks, hills, craters, etc.: -1 to hit
Ruins, walls, purpose-built defenses: -2 to hit
Bunkers or buildings with AV values and firing ports: -3 to hit (you can try to target the unit inside at -3 to hit or the building itself vs the current rule of only being able to target the building)

Speed of Target:
Target moved 7 - 12": -1
Target moved 13 - 24": -2
Target moved over 24": -3

Movement of Shooter:
Stayed stationary with Rapid Fire, Assault, or Pistols: +1
Moved with Heavy Weapon (for infantry): -2


Misc:
Overwatch needs a 6 to hit (ignore all modifiers; only a natural 6 will hit)
Being at higher elevation: +1
Jink: -1 (weaker than current rule but it combines with the speed the bike moved)
Skilled rider jink: -2
Night fighting, Stealth, Go to Ground, etc. -1 for every +1 modifier to cover save
Anything that says "Snap Shot" that is not covered here already: -2 (fliers are covered by Speed modifier above)




Armor Saves:
Use modifiers instead of the AP rule. 1 always fails.

A weapon's save modifier is 6 - the AP value.
AP6 = no modifier
AP5 = -1 save
AP4 = -2 save
AP3 = -3 save
AP2 = -4 save
AP1 = -5 save

No re-rollable invulnerable saves.
Terminator armor is 2+ AND 4++ (not either/or).





Melee:

To-Hit:
Updated to-hit table that accounts for every difference in WS between attacker and defender. With every point of difference, you gain either a better chance to hit or a lower chance to be hit in return.

Challenges:
You can decline a challenge and still fight and still use your LD value. But if you offer a challenge and the other player declines, you add +D3 to the number of Wounds inflicted for the purposes of determining the combat winner and morale check of the loser. I would like there to be some incentive to accept a challenge, but not such an overwhelming penalty for declining, especially if it is suicide to accept.






Vehicles:
Armor:
Vehicles keep AV but also get a base armor save based on their HP, modified as normal by the weapons.
Up to 3 HP: 3+ save
4+ HP: 2+ save

Most anti-tank weapons will pretty much negate the save anyway, but it gives some defense against masses of anti-infantry fire. It seems a vehicle should at least have a comparable armor save to an infantry model. For example, it feels wrong that a Sentinel is easier to kill with a heavy bolter than a tactical marine, despite costing 2 - 3 times as much for the same weapon loadout.



Embark/Disembark:
If a vehicle does not move, the riders can disembark and charge in the same turn, even if the vehicle is not open topped or an assault vehicle. I seriously doubt this will make Rhinos overpowered in any way, and it just seems more realistic and fun.
If the vehicle is an assault or open topped vehicle, it can move up to 6", disembark move and charge, as per the current rules.






Morale:
+1 to morale checks (to break or regroup) if you are in cover or out of LoS of any enemy.
-1 to morale checks due to shooting/psychic if you lost 50% or more of the unit in one phase. 



Characters:

Look Out, Sir
Only applicable to designated bodyguards/retinues and a 4+ roll.



Weapons:

Sniper Rifles:
These seem pretty useless and never seem to get used.
Option:
Can be fired as normal or with the option of a "Called Shot": -2 to hit, but then the shot is S8, AP 3, Precision Shot.
And they should cause Pinning. Am I just remembering wrong, or didn't they used to?