I just downloaded Mocha trial - learning version to learn how to blur faces. I have pretty good grasp of Mocha tools so far except i am unable to figure out these things:
-how to apply blur (i only see solid mask available)
-how to delete unwanted keyframes
You should be doing this within the BCC 10 filters, not within Mocha Pro. To do this, first download the trial version of the BCC 10 filters for your host ... you can access them at http://www.borisfx.com.
Once you've downloaded and installed BCC 10, apply the BCC Pyramid Blur filter to a clip. In the effects control panel, you should see a button labelled launch mocha. Click that button to launch mocha from within the BCC Pyramid Blur filter. From there, set up create the mask shape that you need and close mocha (it should save automatically.) The result of this should be that you have isolated the blur to within the mocha mask.
Keyframes in mocha are in the Dopesheet tab of the mocha UI.