What is the ruling on a person who frequently travels between his city of residence and his place of work entering into a state of ihram for 'Umrah and shortening and combining prayers?

Umrah: One who intends to perform Umrah must enter into ihram from the miqat. So, whoever is from Riyadh or Dammam should enter ihram from the miqat of the people of Najd. Whoever is from Madinah should enter ihram from the miqat of its people. As for whoever is in Jeddah and intends Umrah, they should enter ihram from Jeddah.

Shortening Prayers (Qasr): One must pray the full prayer in their hometown, and when intending to reside in a country for four days or more. It is also advisable to pray the full prayer in the country where one's wife resides, to avoid dispute.

Combining Prayers (Jam‘): It is permissible where shortening prayers is legislated, and it is permissible when there is another valid excuse that allows it.