GK Reserveration form

Is it possible to use the GK Reservation form twice, with different settings?

Thank you in advance!

Hi,
none, it's plugin not a module.
But if you need a real booking system I suggest to check Solidres extension, it has also module inside.

Ok - thank you!
Is it possible to add "date-field" from GK Reservation to GK Contact?

In theory yes, but it must be added by php developer.
And officially we cannot help in customizations.