Integration

I open this thread to discuss about the compatibility of using .NET and BPEL. Currently, I'm trying to
- Implement some basic Web Services using C#.NET.
- Using BPEL in the Orchestration level
- Invoke the process using C#.NET Client

Some problems that I encounter so far are
1. The BPEL Process's instances after being invoked by .NET Client are still in the BPEL Server, which can only be killed manually.
Is there any API that I can call from Client side to kill the instance after it completes? As I'm not sure whether leaving process instances on the server will degrade the performance.

2. I just write a HelloWorld BPEL process like the Tutorial 1, but using ASynchronous BPEL Process which consists of the "initiate"->"assign"->"onResult" operations. From the .NET Client side, I try to call the initiate() and onResult() function but NO string message received.
So, how to actually invoke the BPEL Asynchronous Process from the .NET Client?

Please let me know if you have the answers. Do appreciate. Thanks !