Why not create another property for example oldName where you keep the old X value in it. You can hide it by not displaying it to the user and you can still reference to it in your code to pull the old values etc. 

The answer to your first statement is Yes. If you want to create a different set of metadata schema for a business use case then you can do so by following the same link. Click on Create --> Create schema form. BTW these schemas in 6.2 are created and kept under /conf/global/settings/dam/adminui-ext...

The login credentials including hostname for your AEM instance will need to exist in your maven build script.

in AEM 6.2 the correct way to do what you're trying to do is through  "metadata schemas" Here is the doc.https://docs.adobe.com/docs/en/aem/6-2/author/assets/managing-assets-touch-ui/brandportal/metadata-schemas.htmlThis would allow you to change the default schemas as well as introduce new ones. Ev...

Try this @Component@Servicepublic class AlfrescoConnector implements WorkflowProcess {    @Property(value = "Alfresco CMIS Connector.")    static final String DESCRIPTION = Constants.SERVICE_DESCRIPTION;    @Property(value = "Adobe")    static final String VENDOR = Constants.SERVICE_VENDOR;    @Prop...

What do the replication logs say? Have you tried using an admin account to see if it works?In replication logs do you see a - INFO - publish : << HTTP/1.1 200 OK if not check the ACL or the replication agent. Do you see cq:lastReplicationAction ?