The reason this is an important issue is that many of those in Congress, currently, are merely there to protect their paychecks.
Addressing each issue:
1) 4-year ONLY term: Congress, like Supreme Court Judges, have no tern limit. Supreme Court Judges have earned their right to stay a life's term through years of study- not so with Congressmen. Congress had become the equivalent to Parliament. The President has no actual power - he is simply a figure-head.
2) Age limit (28-50): We need officials who understand modern technology, our current economy and whom actually can relate to and understand modern-day society, as well as its pace. We need modern-day innovators, not individuals set in their their ways with refusal to accept any change-especially not for the "common man".