Recording a Powerpoint presentation together with a PIP video (not broadcasting)

[notapro]

Total rookie here. I've got a powerpoint presentation together with a video (with audio). Expected result is a recording containing a full screen ppt slides presentation together with a small PIP window container showing the related video w/audio (again, already recorded, working and available, there's NO broadcast here) .
I managed to put together both sources (i.e. my ppt file as a Windows capture and my mp4 file as a Media Source), please see attached screenshot.
Starting recording how am I supposed to:
1: listen to embedded video/audio in "preview mode" as I can see the video going and Media Source bar moving in Audio Mixer yet I cannot hear any audio
2. start embedded video from the beginning (video starts automatically as I add the source and I see no way to stop, rewind and start it from the beginning on command as I start recording)
3. manually move ppt slides forward from time to time accordingly to the audio/video presentation.

Provided this can be done using OBS Studio.

 

[notapro]

I managed to activate Media Source audio monitor. Still in need for a reply for questions 2 & 3. Thanks

 

[notapro]

I've found the media bar too, so that only last question still needs a reply: how can I manually move ppt slides forward accordingly to audio presentation during the recording?

 

[notapro]

Solved last one too. Never mind... ;-)