Questions on OPP and AP

I have an additional question on the Media Sets..

I found this on the Admin Guide:

The append period starts when the first
backup job is written to this media

For example I have a media set of 4 tapes, as I understand they have the same attributes such as OPP & APP.

Questions:

1. Will the OPP expire at the same time for all tapes of the media set or is it a per tape basis depending on when was the specific tape last written to?

2. Will the APP expire at the same time or is it a per tape basis depending on when was the specific tape first written to ? (The first second data was started to be written to tape)

3. You adviced one job per media set.

 Can we have multiple jobs write to the same media set ? For Backup Exec 2012, as I remember we could have multiple jobs write to the same tape or tapes.

Thanks,

Paul