
Explanation

Box 1: No
Azure Advisor does not generate a list of virtual machines that ARE protected by Azure Backup. Azure Advisor does however, generate a list of virtual that ARE NOT protected by Azure Backup. You can view a list of virtual machines that are protected by Azure Backup by viewing the Protected Items in the Azure Recovery Services Vault.
Box 2: No
If you implement the security recommendations, you company's score will increase, not decrease.
Box 3: No
There is no requirement to implement the security recommendations provided by Azure Advisor. The recommendations are just that, 'recommendations'. They are not 'requirements'.
References:
https://azure.microsoft.com/en-gb/blog/advisor-backup-recommendations/
https://docs.microsoft.com/en-us/azure/advisor/advisor-overview
https://microsoft.github.io/AzureTipsAndTricks/blog/tip173.html