Is zakat obligatory on end-of-service benefits, holiday pay, and the value of travel tickets if one does not travel? And is zakat obligatory on a monthly salary of 3800 Saudi Riyals, knowing that there is compulsory zakat paid in Sudan?

End-of-service benefits are not subject to zakat (definition) until they are received. They are then subject to zakat for one year, because they are like a debt owed by a procrastinator. As for the salary, there is no zakat on it unless a full year has passed while it is in one's possession and it reaches the nisab (definition). What the state takes with the intention of zakat is counted towards it, and whatever remains of the zakat must be paid.