AFAIK Kevs gear will do NO damage to your bike in the short,medium or long term...they WILL allow the bike to run smoother and imho allow it to run as it arguably should have when it came out of the factory.They allow a generic set of parameters across the range(s)..
PCV allows a bespoke map to be 'made' for your bike..or you can download a map from here that is close to your bikes mods and see how it feels.
Personally I was happy with similar mods to yours BUT couldnt resist a PCV when it came up on ebay at the right price.