If I delete an audio clip, does it still count against my monthly/annual total?

Only audio files that are downloaded or used with the Combine feature will count toward your subscription allotment.

Each time you render an audio file, your clip count will go up. Each audio file is then eligible for credit upon deletion. Only two actions will make an audio file ineligible for credit upon deletion:
1. Downloading an audio file.
2. Using an audio file with the Combine feature.

This video provides more detail on how your clips are counted.