The only problem with your claims is that they are flat wrong. For example, the elimination of the “public option” a central portion of the original plan cannot be characterized (at least by honest people) as “insignificant.”
But let’s focus on the timeline for Obamacare.
January 2009: Obama sworn in.
February 2009: In State of the Union address Obama states intent to work with Congress to reform healthcare.
June to September 2009: Senate Finance Committee holds series of 31 meetings to develop a bill. The group includes Republicans Mike Enzi, Chuck Grassley and Olympia Snow.
July to September 2009: Nearly 60 public hearings related to the legislation are held that includes testimony from health insurance industry experts and representatives, consumer representatives, and healthcare provider experts and representatives.
August 2009: During Summer recess members of Congress discuss the proposed legislation with constituents.
November 7, 2009: House passes the bill on 220–215 vote. Please note the distance between this and the House passing Obamacare repeal before even getting CBO scoring of the bill.
December 2009 Senate Debates bill for 25 straight days before passing it by a 60–39 vote.
Due to differences in the Senate and House bills the process then goes through the conference committee process. The Democrats could have, but did not use the reconciliation process (that the Republicans are trying to use) to compel passage of the bill with less than 60 Senate votes.
March 21, 2010: House passes Senate version of bill by a 219–212 vote.
March 23, 2010: Obama signs bill into law. He has been in office over year.