Dear Rachel,
I can only go on what my old Airlines policy was in the UAE.
Leave is on a seniority position. Only every 4 years could you put in for Xmas or New Year. You could only have one or the other, so it was fair for all crew.
Normally, you could bid for days off prior or after you leave days max 2-3days. So crew would normally bid for a long haul flight, have the days off to extend their leave and then bid for a long haul flight after there leave to extend it, if that makes sense e.g 11 day trip had to have 2 days off before, then leave, then 2 days before on 11 day trip.
However, this can change if you dont get your bids and you normally only need 12 hrs after your leave to fly again.
You could put your bid in and then, always see if someone would swap with you.
As for abuse from paxs.
All airlines in the Mid East, have a policy that crew are there primarily for safety. No abuse of any form is tolerated by the Airlines. You write something called a VR (voyage report) that gets sent to the CCMs, and they will follow up. Fights and things do happen, restraint devices are used in the Airlines and the police and security in Mid East countries are great. They are very understanding. Statements are taken by the police in case of prosecuting.
The Airlines in the Mid East are very conscientious of their staff in respect to any safety issue. However, tolerance of crew being rude or verbally explicit or threatning they will not accept.
I hope this helps to answer your question.