CloudSync is a Salesforce Native Application to migrate Salesforce Records from one Salesforce Instance to Another Salesforce Instance.

Yes, Salesforce records will be migrated directly from one Salesforce instance to another Salesforce instance without any middle layer.

Yes, we can migrate records from Sandbox to Production, Production to Sandbox, Sandbox to Sandbox etc…

Yes, we can migrate records between cross Salesforce instances.

Yes but those objects should be related like Account-> Contact, Opportunity or Opportunity -> Opportunity Line Item.

Yes, you can select the owner mapping when you are configuring the migration.

Yes, You can configure the record type mapping.

Yes, We can Migrate the Fields based on a Clause. Need to Write Query, SELECT Id FROM Account WHERE Id = United States

Yes we can Migrate only Custom Fields of a specific object. Need to write Query, Example: SELECT ID, Name, AccountNumber FROM ACCOUNT

Cloudsync in available on the AppExchange.