1. If earthly attachment is inherently "lower," why does a genuine Buddhist remain on earth at all? Insisting on staying and experiencing life in some form or other certainly seems to be indicative of attachment. Why not "detach" entirely, if you know what I'm sayin'?
Buddhas themselves remain on earth to teach the path to enlightenment.
Buddhists in general remain on earth because this life is most important. Even among Buddhists who believe in enlightenment, the goal is to perfect yourself as much as you can in this life so that you can get closer to achieving enlightenment in the next life.
Suicide itself is seen as a bad karma among those believing in enlightenment. It might take you further away from your goal of enlightenment.
For buddhists who do not believe in enlightenment, all that we do is for this life so taking it away makes no sense anyway.
2. Please attempt to express what "Enlightenment" is, since it is a goal you are pursuing. Surely one must have some understanding of a goal one is in pursuit of.
Enlightenment is a very very complex thing to explain and I don't have a lot of time to explain it here. Enlightenment is, in brief, the ultimate goal of Buddhism as in Buddhism suffering is the problem of life. All of our problems are due to suffering of one form or another. When Buddhism refers to suffering, it means mental sufferings not headaches and burns and such. What causes mental sufferings? Many things but attachment is the main cause of suffering because, if we are not attached to anything and crave nothing then when we don't get things it will not affect us.
Enlightenment is about realizing the truth of reality, ridding ourselves of suffering, improving our knowledge to super-human levels (self knowledge), understanding ourselves and others, separating ourselves from our egos, realizing that all is one in this universe, enhancing our emotional powers with overflowing motivation, energy, inspiration, wisdom, love and caring. Enlightened beings (Buddhas or Arahats) love everything as if it is themself, because they see that everything is part of them as they are part of everything else. Separations between "I" and "them" are imaginary. Enlightenment realizes a level of mental mindfulness which is more pleasurable than any physical pleasure known to man, and that is why
Buddhas do not have sex. Having sex for a Buddha would be sort of like playing tetris on a cracked blurry cellphone while hiking in the most pristine and beautiful meadows and mountains in the world, or playing tic-tac-to on a dirty napkin while sitting on the most amazing beach in the world. It would be a distraction and it would take away from enlightenment experience due to the fact that it doesn't stack up at all. This is what Andreas does not understand and realize why this is important for Buddhists.
Beyond that, Enlightenment can be described in 10 thick books and still it would not touch the surface and still...enlightenment can never be comprehended by anyone UNLESS they achieve enlightenment. It would be like describing a rainbow to someone who has been blind their entire life, or a Beethoven symphony to someone who has always been deaf. Just is not possible.
3. Does Buddhism have any sort of punishment in store for the heathens like andreisman?
Depends on the Buddhist school, though in my opinion NO. There are no punishments in Buddhism other than those punishments that we inflict upon ourselves due to
our OWN ignorance. If I walk into a hall full of pointy nails then I'll get stabbed with nails. This is a result of my action. Not a "punishment" by any means, just a result.
What is the result of not following the path to enlightenment in Buddhism?
You don't become enlightened.