I just checked with the AMS team and the right avenue to start is contact Adobe CSM/TAM for your account and they can help you get in touch with some from AMS. AMS team will perform analysis and provide you detail steps that need to be performed for migration.

You can use the GET command below:  http://<host>:<port>/etc/packages/my_packages.infinity.json Where "my_packages" is one of the folders under /etc/packages where packages will be stored. You can replace this with your custom folder name.

By default, AEM will keep the user logged-in unless user logs out Or the token is expired which can be configured at [1] [1] http://<host>:<port>/system/console/configMgr/org.apache.jackrabbit.oak.security.authentication.token.TokenConfigurationImpl

I can confirm, location of /etc/map has not been changed in 6.4 Or 6.5

How to migrate/setup author+publisher+dispatcher in AMS ---> Migration is seamless and mostly similar to on-prem. AMS/Daycare team should be able to help you if there are any issues during the migration. For Responsibilities, refer to [2] More details about AMS program at [1] [1] https://helpx.adobe...

You can look into creating the CURL command when you try to extract a sample file from the assets UI. Check [1] for more details.  [1] https://helpx.adobe.com/experience-manager/6-3/sites/administering/using/curl.html#BuildingacURLReadyAEMCommand

I would recommend setting up a DEBUG logger on com.day.cq.replication to verify if the alias deactivation is getting triggered and then change the dispatcher log level to DEBUG to verify what's happening on dispatcher when this kind of request is requested.

I believe magento is running on port 8081. If thats the case, Can you try to run magento on https and try again?

Do you see anything in the log files when starting the instance?Are you installing SP2 via crx-quickstart/install directory?Did you stop the instance after SP2 or it automatically stopped?

When you run the groovy script, It will list the paths that have been corrupted.You can then delete those paths using the groovy script and create a package of these nodes from other instances.