The black dust is from the TPS itself. Just a by-product of normal wear. The more dust, the more wear that has occured. No need to disassemble further if it's running o.k.
Trevor, I wish it were that easy, it would make my life less miserable.
My experience has been that spikes and/or small glitches will be counted as actual events and the system will react to them. There is no buffer or lag time allowed. If the computer is fast enough to see the event it will react accordingly.
Newer control units employ fuzzy logic in some areas, such as ABS inputs, but I haven't witnessed any yet that can/will sort out an erratic signal. Too many times I've seen one or two spikes in a TPS or crank signal all but bring an engine to its knees. I agree, it's ridiculous to be that critical, especially considering the harsh enviroment of an automobile. One could easily build a conspiracy theory against the OEMs and back it up, as there is at least one GMM that knows enough about automotive signals that it will take 'snapshots' of a glitch as it occurs, unattended.