Hi Paul,
Thanks! To answer your questions:
1. No there are no plans at the moment to remove this requirement. Also remember that the checksum process of the backup serves to ensure that the backup copy is healthy. Even though you checksum the active instance via the OLM task, it does not verify that the backup you just took is healthy, which could then lead to problems if you have to restore.
2. Thanks for that point. No in this article, we are strictly referring to the LCR and CCR passive copy. SCR does not provide a means to back up the database via an Exchange aware solution (VSS or streaming backup). However, you could utilize the steps mentioned in "Streaming Backup of Active Copy" to validate the health of the SCR copy.