C#, hands down. F# wouldn't be bad either, but it is a primarily functional language, meaning that its interaction with .NET's object-oriented libraries can seem a little contrived at times.
This is easy. C# and the .NET framework. It easily exceeds all of your requirements.
Yeah, C#/.NET is the way to go, although VB.NET or Delphi would be OK. Delphi appears to be picking up steam again, possibly because Delphi apps don't require redistributing the .NET framework.
C# and Winforms is probably the easiest. It resembles C++ in many ways without the pointers. It has also taken a number of features from Java though the form layout is different.
You would also be able to use C# if you wanted to learn WPF (Windows Presentation Foundation) the successor to WinForms.
Visual Basic would also be a reasonable possibility as it reads in english relatively easily.