Quick answers:
-Why have Saints, raised up HIGHER than other people?
Saints who are above the rest of humanity and even above other Christains are a teaching of Catholicism. I don't subscribe to it, irrelevant
-Why have Sinners, dropped LOWER than other people?
Ditto
Caveat about the above two answers, since I'm not sure if you were referring to the catholic teaching on saints. If the question is really about the "saved" vs the "sinners", yes there would be a demarcation line. Sinners => guilty, saved => innocent. The the only difference is that saved have had their record expunged, while the sinners have not. God's desire is that all the sinners would seek Him to have their record expunged, but a truly loving God also has to be just and thus won't force people to choos Him or pardon them in spite of their rejection of Him.
-If we're all equally sinful/guilty, does that not also make us equally good/innocent?
Yes. Compared to each other none of us is better or worse than another, but not by the metric you use. By human metrics this isn't the case, but by God's metric it is.
-If we're all equal morally, why be MLK instead of Hitler? (HA! GODWIN'S LAW!) ;)
If both are headed to hell (and I'm not claiming either is or isn't), what exactly was the point of being one or the other? It makes no difference... The life one lives is not the point, the allegiance is. Note that if one truly repents of rebellion and accepts God's offer of a pardon, they have alligned themselves with God, a "righteous life" is the result of the transformation God offers along with the gift of pardon. Thus Hitlers wouldn't exist among the saved except as posers who aren't really saved. Note that God doesn't offer perfection and sinlessness in this life, thus Christians aren't perfect, but their lives should reflect the desires of the God they serve.
Done with the trivial questions.
-If we're SET at negative infinity, how are INIVIDUALS culpable for a race's Fall?
This assumes the Human race was created as individual entities which is a western idea. I don't adhere to this idea. Eastern philosophy understands this better than we do. Take a radical muslim family. If one member of that family brings dishonor to the family by breaking the law, the whole family and community are dishonored, and thus funerals for living family members and honor killings. Eastern cultures (primarily religious cultures) take for granted that one person's actions are not without effect on their family, neighbors and community. Annimistic religions are replete with instances where the witch doctor tries to exorcise the village of demons because the actions of one or a few were assumed to have brought consequences to the whole village or community. It is simply not a question of whether or not the rest of the village did anything to cause the problems. Note that this is how the ancient Jews viewed things as well. Israel thrived or floundered as a nation. They went to war with their neighbors and put entire races to death because of the child sacrifice practiced by some in those neighboring cultures. (I still owe you a separate thread on this topic, btw.) This point is one that I disagree with much of Western Christianity, in that I think they have embraced a non-biblical concept that the individual is more important than the community. If Humans were created as communal organisms, then the explanation of one member's fall easily explains the dire straits of all.
-If individuals are NOT culpable, and the race is wholly damned, why have a Heaven?
Individuals are culpable. The human race being damned does not exonorate the individual who is a member of that race. However, the "second Adam" Jesus Christ redeemed the Human race, and paid the penalty that was due the human race. He faced the prospect of eternal separation from His Father at the cross, but was found innocent, while paying for our crimes. Now the individuals in the human race have a choice. Who do they align themselves with? Their old father Adam? Or the "new Adam" Jesus Christ? There has been a split in the human community if you will. One segement will follow the old community, while one segment has chosen to follow the new. The offer is extended to all but some reject.
-If individuals ARE culpable, how, if they were suffering the Sins of (Adam) the Father?
Sin is threefold. What you do that you shouldn't, what you don't do that you should, and the state you are born in, the disease part if you will. The first two are symptoms the third is the cause. Because of the disease, they have exhibited their own symptoms. You pay for your own sins, among which are the sins you caused others to commit. A parent who doesn't raise their child to be a good citizen and models theivery and murder to their child is in some sense responsible if that child follows in their footsteps, however the child is also responsible if they make the same mistakes as their parent. See my above discussion and if that isn't clear I'll answer your follow up questions. And I do disagree with Draugnar on this point.
-If humanity IS at negative infinity and fallen, as you say, why doesn't Loving God FIX IT?
He has by dying for His creation. The fix is in place, the cosmic war is won, and all that remains is to mop up the resistance, but God is patient and not willing that any should perish, thus he gives us more time than we deserve. He is not interested in a quick end. He is in the buisness of saving people, thus he chooses to wait so that more will choose Him.