Ran into a situation where my opponent had deploy the Dazer. I moved my Teutonic Knight up, and was in the area of effect. On the next order I wanted to declare an Assault. I understand that Assault is effected by Very Difficult Terrain, but it is not clear to me how it is effected. In the case of the Teutonic Knight, his MOV is 4-4, so the second MOV skill value is 4. Assault is a single Movement Skill, adding up the two values of the MOV attribute, so I'm not moving a second time. As such RAW appears to indicate that Assault is actually uneffected by Very Difficult Terrain, resulting a Mov of 8", followed by CC, which is unlikely to be RAI.
I think this is a kindred question to "can my Tanko also Move when my Domaru Assaults?", and since the answer there is that you don't actually sub-divide the declaration into three skills, I say Assault inside Very Difficult Terrain would be a total of 2nd MOV+2nd MOV, or in Teuton/Domaru's case 8". Edit: as long as you actually start inside the zone, 'cause no crossing the boundary without the appropriate terrain skill.
Sorry, that's not what the Wiki says: "Assault is an Entire Order made up of the Short Movement Skill Move + CC Attack." There is a single short movement skill, the first one.
In either case, you should resolve like any other Move. You make one Move the value of the sum of your movement, and this would still be modified by terrain. If the trooper chooses to continue to move through the Very Difficult Terrain area, he must declare a new Order and suffer the following effects: In Very Difficult Terrain, troopers use only their second MOV value. In Very Difficult Terrain, troopers cannot declare two Short Movement Skills in the same order. The assault order only contains one short movement skill (and even that is debatable because CB is not very consistent with nesting skill behaviors and labels), so I guess that is correct, a 4-4 trooper would still have an 8 inch Assault in Very Difficult Terrain.
No, Assault is not two Move skills glued together followed by a CC Attack, just like Entire Order Super Jump is not the same as declaring Jump twice. For both skills, it's one move that covers the combined distance, not two moves.