- Motto: "Ain't nobody got time fo dat....."
- Weapon: Null-Ray Rifle
This is a fantastic question.
For starters, I think without all the components, combination is impossible or, in the case of as you said, Bonecrusher being removed, combination is impossible to maintain.
since, as Rodimus said, a combined form merges the consciousness' (what?!?!?) of multiple robots, I think each individual would still be conscious of itself but unable to function on it's own. In the Dreamwave MTMTE books, for the Technobots I remember most clearly, that each of the five serves a separate 'cognitive' function as individual robots, and then that part of the shared mind forms that same purpose for the unified mind. So, and these are not exact here, Afterburner would be the team stratagist and thus the strategic element of Computron's mind; Nosecone would be the group member who deals with something like battlefield analytics, and thus the part of Computron's mind that deals with threat assessment and response; Strafe is listed as the 'gunner' and thus is mentally responsible for Computron's targeting and firing process.
So each individual does something for the team, and becomes that part of the wholes' shared mind.
Without each of these pieces, the whole is unable to form itself, so if one member is hurt or missing, combination becomes impossible. AND, purposely excluding Scramble City, this would also be why members of other teams can't join other teams' combined forms. You couldn't have Brawl and Breakdown as limbs of the same combiner because Brawl and Breakdown both serve the same purpose for their respective teams (just an example, not necessarily true).
The more successful of the combined teams are more successful because even though the individuals serve individual roles within the team, their overall mentalities are aligned enough that they would merge into a composite mind more smoothly and seemlessly, so Predaking works better than Menasor because the Predacons don't have the same level of internal team strife that the Stunticons have. In the instance of Devastator, while each of the Constructicons are intelligent engineers, they each (again, Dreamwave MTMTE here) have strong sadistic or masochistic (Scavenger) streaks as individuals, but they all serve essentially the same function within the group. So, Devastators' mind is not encumbered by things like tactics and trajectories, because all the Constructicons basically are 'warriors,' allowing for the sadistic or repressed rage of each to be their dominant mental characteristic as a single unit.
I'd imagine the individuals would 'see' whatever the combined mind sees; all the individuals would experience what the combined form experiences simultaneously. I seem to remember G1 episodes where Superion (or whoever) would get shot in the chest and separate, to have all five Arealbots holding their heads and appearing injured, not just Silverbolt, who would have been the physical chest that was shot. So, each member would have the experience of being shot,even if maybe the arm/leg dudes didn't have physical damage indicating they were shot, they'd feel the pain and its after effects.
I guess by that rationale, the individuals would remember being Bruticus, not just like Swindle and Brawl would remember walking since they are the legs, and Blast Off would only remember punching something or pulling a trigger. Each one would remember being Bruticus, which really makes me feel better for poor Long Haul, who would only have memories of being Devastators' crotch.
Man, that was fun. I'm so glad I stumbled across this thread. Sorry if anything isn't clear, and hopefully if this thread continues I could get a chance to clarify. I got so excited that there was a thread that wasn't movie-based whining, my fingers just went wild.
I really hope we get more participation in here!