gcc + Windows + general questions

[Soeren Grimm]

Hi,

currently we are using Visual C++ 6.0. But somehow the VC Compiler
is not standard compliant. So we wanna change to gcc, but not change
the OS.
So i have some general questions about gcc under Windows 2000.
Is it possible to compile pure windows application with gcc?
Is it possible to compile Qt applications?
How is the performance compared to the Intel or the Visual C++ 6.0
Compiler.
I am not sure of i am allowed to ask this, but i ask this anyway ;-)
Is there a way to integrate the gcc into the Visual C++ environment,
like
the intel compiler?

Thanks in advance
Soeren