I'm not sure how this works, so I have some questions.

Do I have to book a long (say, 48 hours) layover beforehand applying for the visa or can I apply for the visa with a standard ticket and they will allow me to change it for free? (sounds unreasonable)

I have a ticket from an agent. The route is KRK-TXL-AUH-BKK-AUH-TXL-BUD. The flights are operated by AB, EY, EY, EY, EY, AB. The flights are marketed as EY, EY, AB, AB, EY, EY.
This offer is available to all guests travelling on a return Etihad Airways operated or marketed flight (with an EY flight number) beyond Abu Dhabi. This offer is not applicable for travel where Abu Dhabi is the final destination. Offer is valid for a minimum of 2 nights stay in Abu Dhabi.
1. Would you say that all of above flughts are operated or marketed by Etihad?
2. Does this count as return flight, or is it a multicity?