So you're looking to recreate the sync feature that Kentico already has? What performance issues have you experienced? What indexing issues have you experienced?
Maybe a deeper look around those two questions would be a better start to determine if it's really Kentico or if it's some other underlying issue.
Secondly, there is already a tool created that should work with KX13, which is more advanced than the OOTB sync feature.
We've used Kentico since 2008-09 timeframe and we've had our fair share of syncing issue and the majority of our issues have typically been created by custom code we had implemented or improper configuration.