how can i fix my high revs and juddering for my gilera dna 50?

Quite simply, i have a gilera dna 50

It has been de-restriced and reaches 50+ MPH

The problem is, the bike pulls away at 7000 rpm, and cruises at about 9000, i know no one else with a DNA, so i have no idea if it's normal. It does seem incredibly high and i would like to know how to improve this and hopefully pick up my acceleration