1 - You should probably add the Windows
unit to the uses clause to make those types available, then.
2 - You're using Delphi 2007, but the date of the article you linked for Indy Bluetooth Support
is dated in mid-2011. It's most likely it was written for a more recent version of Indy than the one that shipped with Delphi 2007; you'll probably have to either upgrade your Indy version or modify the source of Bluetooth.pas
to downgrade it to your Indy version.
As far as your "Another question", that would be just that - another (separate) question, since an answer to it now would be meaningless until you can compile Bluetooth.pas
successfully.