Even more convenient for sync ... drop several tracks onto the timeline, right-click on one of the audio tracks and SYNC AUDIO.
For camera switching, right-click in the preview window to see if clicking on PREVIEW MODE offers a MULTICAM MODE option. If this test feature is unavailable, reinstall Videopad - perhaps several times - and it may appear. No need to re-download.
Position the cursor where a camera switch is to be made. Click ADD SWITCH.
Check the box for the track for the camera track to be used from that point on... 
Do the same for each camera switch. Note that there's also a REMOVE SWITCH button. Or right-click on the switch
.
Here's an example of how the sequence might look. Video began with cam 2, then switched to 3, then back to 2, then to 1....
