using phone's mic while a heaphone is connected

First of all,  Thank you very much for this wonderful application.It solved my xperia z audio toggling hardware issue.

Now my question.Is it possible to use the microphone on the phone to answer a call while using a headphone to listen to the call?
I couldn't find the setting for that in the app.It is very difficult to answer a call when I am using a headphone (no mic).

Besides there are few other issues that I would like to bring to your notice

1. Whenever I plug in a headphone (no mic) I get to hear the voice say "to use Google voice search please unlock your phone",even though the phone is unlocked.However this doesn't happen with headsets with mic.

2.While on a call if i use the widget to toggle the call gets disconnected.

My phone is an Xperia Z with build 10.5.1.A.0.283 running on Android 4.4.4
Please assist me with the issues.

Thanks