Several initial thoughts:
Wasn't He supposed to return in the clouds and be seen by all? Wasn't there supposed to be angels and trumpets and much ballyhoo?
think about where the clouds are located. They are located in the sky, not on earth, but above the earth. We normally associate the sky above the earth to be the heavens.
Coming with the 'clouds' should be understood to mean the kingdom will be in the sky above the earth where we see the clouds....otherwise known as heaven.
and if that is true, then unless we can actually see into heaven itself, we should not expect to be able to visibly see Christ on the throne or coming with the Angles. Even he said "the world will behold me no more" and this explains why he gave his disciples a 'sign' to signify his presence in the kingdom. If he thouth his disciples would be able to see him, then he would not have needed to tell them what 'signs' to look for.
He's ruling as an eminance grise? Whose His front man?
If the war, strife and starvation in our present world is any indication, He doesn't seem to me doing much of a job.
Who is his frontman is a very good question. Obviously his frontman would need to be someone prominent within the realm of his christian followers on earth. But more then that, they would need to have knowledge of the kingdom and be actively working to promote it as Jesus and the apostles did. They would also need to uphold Gods laws and their congregations would need to be clean....they would need to behave as ambassadors as the apostles did:
2Cor 5:20
 Therefore, we are ambassadors substituting for Christ, as though God were making an appeal through us.
And as to why there is still so much trouble on earth, well that comes down to the very first action taken by Christ when he took power... he cast Satan out of heaven and confined him to the earth.
This act directly impacted the earth because Satan has been on a rampage and has been influencing people to act against God and his righteous standards. Historians all confirm that since the first world war in 1914, the earth went into a new era of violence and trouble.