Access for Code Artifact

Based on the information available, I can address your first question about granting AWS Artifact access to developers in a separate account.

To grant AWS Artifact access to your 10 developers, you should follow these steps:

1. Create an IAM policy that grants the necessary permissions for AWS Artifact. You can use AWS managed policies like AWSArtifactReportsReadOnlyAccess or AWSArtifactAgreementsReadOnlyAccess depending on what access they need, or create a custom policy.

2. Create an IAM group and attach the policy to this group.

3. Create IAM users for each of your 10 developers and add them to this group.

This approach allows you to manage permissions centrally through the group rather than assigning permissions to individual users.

For cross-account access, you would need to set up IAM roles with appropriate trust relationships between accounts, though specific details for this scenario aren't provided in the available information.

Regarding your second and third questions about connection renewal and proxying third-party private repositories, the provided information doesn't contain specific details about these aspects of AWS CodeArtifact (which appears to be different from AWS Artifact that the sources discuss). AWS Artifact is primarily focused on compliance reports and agreements, while your questions seem to relate to CodeArtifact, which is a package management service.
Sources
Granting user access to AWS Artifact - AWS Artifact
Using AWS managed policies for AWS Artifact - AWS Artifact
Identity and access management in AWS Artifact - AWS Artifact