To point (3), it's true that you can't resume an audio ad campaign
after it stops running. You can make a new campaign and copy all the
settings over if you want to run the same campaign for another period
To points (1) and (2), this sounds more like a technical issue we
should look at. It's really hard to say without looking into your
account. I recommend contacting the AdWords support to the attention
of the Audio Ads team.