Is it possible to run a standalone app on the DM6446 arm side?

To better help - can you describe what your application/use case is ?

You can build a stand alone app(for both ARM and DSP) using CCS studio software. 

We do not have any such demos

For set up with stack pointers, interrupt vectors etc, there are standard libraries that you can make use of:

One document to refer is : http://focus.ti.com.cn/cn/lit/ug/spnu151f/spnu151f.pdf

Regards

Varada