It’s possible, you can certainly override and customize (replace completely even) the default tickets template. Much of what you are asking about however depends on your ability to hook Gravity Forms into WooCommerce’s processes.
A limitation of WooTickets at this time I should point out is the recording of multiple attendee details when the purchase is made by someone else – however you may be able to workaround that with your own custom implementation.
Ultimately, for anything complex like this, you’ll really need to do your due diligence and spend some time working with and researching the APIs and internal processes of each plugin.
Thanks for getting in touch!