You state the 2043 date correctly and the earlier date (2018 under the "middle" projection - there are 3 projections) where we must cash in bonds for cash also correctly.
It is interesting that the total national debt accumulated from 1776 to 1980 was about $1 trillion - and now Bush has a shot at a one year defict of $1 trillion to add to the current $ 6.8 trillion.
http://www.publicdebt.treas.gov/opd/opd.htmI agree that without reversing the tax cuts - and cutting back on the defense industry welfare additions to Bush's Defense budget - the deficit grows. The payroll tax surplus hides only $150 to 200 billion - and that will decrease in a few years to zero.
And you are correct that pay as you go design means benefits will be then cut - or taxes raised - or we find forieners that want to fund our retires monthly checks in return for paper - a bond - from the US.
Only in the money flow from printing money do I disagree. The printed money is listed as an asset on the Fed books. While it does indeed flow into the system via Federal Reserves open market operations - the Fed trades the cash for bonds purchased in the capital markets - the Fed has other ways to increase M1 and M3 (the easiest is to just deposit the printed money in a bank so that the bank can make loans against their new asset). But this board is not the place to write my first draft of a book on Fed. financial operations! :-)
In any case you are correct - 'printing' above current economic activity needs does little for the economy beyond giving us inflation (although printing below current needs can be a disaster - but with a 12 month to 18 month lag).