Overall thoughts/Cosmetics:
First off most of this proposed patch is very good. The new mission is very good and slightly challenging even on lower difficulty.  I think that all the prestige armor parts are very cool since they are Death Watch themed and I am a fan of the Death Watch. Though there is one exception. The sniper cloak is a little underwhelming with its color. I do think the length of it is great but the color is a little strange for the watch. Perhaps add option to change its color, or make it black since the death watch you know don the black.

The only other cosmetic thing I could think of for feedback would be for the space wolves add actual successor chapters like the Wolf Spear. Though all the great company icons and colors are great

Prestige Perks:

Mainly the perks are decent. Some of the classes are better than others and others are very under whelming. I believe a focus on what the classes do well and are strong at should be reinforced with powerful perks. For example the heavy having a bunch of perks to boost melee make very little sense as it is the fire support class. Perhaps a perk that causes a mortar strike or some type of explosions would be good. Or some type of ranged damage boost the farther away from the target you are. Or an Iron halo perk that boosts damage greatly based of damage absorbed by the halo. The same goes for sniper the perks do not seem to focus on the aspect of it being sniper. Again focus on what the class does well. Assault perks a little underwhelming but boost to health is good. Tactical perks are good except the aspect of having to be below an threshold of health to trigger. Perhaps switch that around so when you health or armor is at a higher threshold they activate. Bulwark is ok could use some more exciting ones around the shield or increased healing. Vanguard has decent perks. Overall perhaps brainstorm some class strength perks as I touched on above. 

Weapons:

The weapon change to allow other classes to use new weapons is great except two things. The inferno pistol should go on assault as it is lore accurate with blood angels as well it could benefit from a melta style weapon since it is a close combat class. Speaking of inferno pistol, it is very cool and feels great to gun strike with. Perhaps a little more damage for it on majors, though the stun is very good. The other thing is give the power sword to the tactical. It is the jack of all trades with the guns let it be the same for the melee weapons. 

Closing:
In closing I feel like the patch will be good and adds some great things. Focus on what the classes do well and play to those strengths. If meta develop let them. The only other thing I could say is think about reverting some healing perks back to where they were. That is the only real downside to gameplay that should be though about is healing outside of stims. Give the classes a way to self heal in some way. This will increase player satisfaction in a big way especially at higher difficulty. It would seem like the gameplay aspect you guys are driving is always being on the edge of death and pushing though. Though that is very space marine and metal, it does lessen the power fantasy. All in all good patch and I continue to love playing this game.