Gallery – disable comments and sharing buttons?

it is possible to deactivate the option to comment pictures in the Gallery?

This should help:
https://jetpack.com/2013/05/01/remove-comments-carousel/

can i have like buttons (facebook, twitter) under each picture?

This can’t be done at the moment, but we’re considering adding such an option in a future Jetpack release. You can follow our progress here:
https://github.com/Automattic/jetpack/issues/231