Explanation

Box 1: No
An Azure AD tenant can have multiple subscriptions but an Azure subscription can only be associated with one Azure AD tenant.
Box 2: Yes
Box 3: No
If your subscription expires, you lose access to all the other resources associated with the subscription.
However, the Azure AD directory remains in Azure. You can associate and manage the directory using a different Azure subscription.
References:
https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/active-directory-how-subscriptions-associa

Explanation:
Box 1: No
You would need to setup the VNET connections, for example with peering.
Note: You can connect virtual networks to each other with virtual network peering. These virtual networks can be in the same region or different regions (also known as Global VNet peering).
Once virtual networks are peered, resources in both virtual networks can communicate with each other.
Box 2: Yes
All Azure resource types have a scope that defines the level that resource names must be unique. A resource must have a unique name within its scope.
For example, a virtual network has a resource group scope, which means that there can be only one network named vnet-prod-westus-001 in a given resource group.
Box 3: Yes
As you build your network in Azure, it is important to keep in mind the following universal design principles:
Ensure non-overlapping address spaces. Make sure your VNet address space (CIDR block) does not overlap with your organization's other network ranges.
Reference:
https://docs.microsoft.com/en-us/azure/virtual-network/tutorial-connect-virtual-networks-portal
https://docs.microsoft.com/en-us/azure/cloud-adoption-framework/ready/azure-best- practices/resource-naming

Reference:
https://docs.microsoft.com/en-us/azure/site-recovery/site-recovery-overview