S,

Clearly Mormonism opens up doors that when taken to it's own logical worldly conclusions are just as illogical or even ridiculous as LDS seem to believe "Mainstream" thought on this is.

Mormonism in its attempt to answer this difficult question muddies up the waters of understanding further and in empowering man limits God.
ya think? Wow...I am of the opposite opinion of course. Mormonism clears up the misunderstandings that have been accepted for thousands of years. Let's consider your point further:

What I think seems to be missing in all this is how central "Satan" is to the LDS plan of Salvation.
True dat--God used Satan so the fall, which was essential, took place. But let's not get lost in the missing implication of mainstreamism either. If God did not think the fall central to His plan, then why would God, according to mainstreamism, have Satan in the garden to tempt and ultimately cause the downfall of mankind? Either way, the conclusion is the same, if you ask me. In fact, I don't see any other conclusion to make.

OR consider that without Satan Adam would never have fallen so "man may be". God in LDS theology placed two conflicting symbolic trees in the garden, the tree of knowledge and the tree of eternal life.
Good point. God, through symbolism, outlined the means to salvation even in the Garden--greatness be to Him.

They were already eternal beings (No need for the tree of life), and as many LDS have taught Adam and Eve were innocent like children not even knowing they were naked. Had they not partaken of the tree of knowledge they would have never been able to follow all of Gods commandments given to them upon being placed in said garden. They were commanded to multiply and replenish the Earth, to do this man HAD to fall. Adam fell that man may be remember. So in the end without Satan no fall, and without the fall no us and no need for a savior, and literally billions of unborn spirits are stuck waiting to gain physical bodies. EVIL as man calls it is central to the LDS gospel, and God within the LDS theology can NEVER conquer it.
I'm not sure how you conclude how LDS belief is even more ridiculous or illogical based on the above. It seems to me just the opposite. Is it worse that God provide a plan, using a rebellious one, to bring about the progress of His creations, than creating out of nothing an evil one to cause the destruction of many to most of His yet to be created out of nothing creations? Its amazing to me that anyone would conclude that mainstreamism is better in anyway. the only possible conclusion it seems to me is that mainstreamism is evil. LDS belief does not force upon God the conception of evil, nor does the Garden scenario make God out to be bad at all. Remember satan, and his designs already were, long before God formed spirits from intelligences.

love,
stem