Hi, I have a bunch of customizations I have done to SuarCRM CE 6.5.8, will these continue to work?

Admin Studio etc- will these changes come along with no manual effort?
custom menus and tabs
custom layouts
custom fields
custom dropdowns

Module Loader - will these plugins likely continue to work?
KReports 3.0
Advanced Open Sales - Invoices etc

Some minor code changes:
Can I expect to be able to implement these to the same source code files, or is the code and files totally changed?