Re: Space Elevators
1) True but emphasis on 'current'
2) Not true. Just nip out to the asteroids and drag back a rock into geosynchronous orbit. Use the rock as raw materials for your carbon nano-tube/unobtanium composite cables.
3) Easy, there isn't any weight (by definition) on the cable at the bottom, so just tie it off with bit of string. In fact it's probably sensible to use a temporay tether - in bad weather you could raise the cable up a few 10s of km to avoid damage. You can always use a balloon as a ferry for the last stretch.
4) Economics + maintenance is just economics. If people want to move stuff off earth in sufficient quantities, or feel elevator rides are better than rockets, it will pay for itself. If not it won't , but we will still have it (see Concorde/Channel Tunnel/most Victorian railways etc).