Seeing as resource contention is a system level problem, I'm wondering why applications should have to fiddle with their environment at all. Is this the norm for audio on Windows or OS X? (Actually I think prior to Vista it was the norm on Windows, but not sure any more)
Might it be simpler to enhance the driver API to allow flagging of devices with scheduling hints, such that the need to tweak the scheduler at all is contained entirely within the kernel? Maybe a rule like "elevate the opening process to realtime priority if FLAG_LOW_LATENCY is set, and the device is not already open,." That could be set somewhere inside ALSA and propagate automatically to user space processes.