Should a traveler who stops over in a town combine Salahs or just shorten them?

Q 1: I often travel to Khamis Mushait which is 350 km away from my home in Bishah. I have the following questions:1- What is the ruling of shortening Salah (Prayer) in this case?2- Sometimes when I intend to shorten the Salah because I will return to Bishah within four days, I decide to stay for more than four days, so I perform my Salah in its full Rak‘ahs (units of Prayer). What is the ruling on the Salah that I shorten before deciding to stay for more than four days?3- I travel from Khamis to Bishah where I live, and shorten and combine Maghrib (Sunset) Prayer and ‘Isha’ (Night) Prayer on my way home. (Part No. 6; Page No. 443) When I arrive at Bishah sometimes people are performing ‘Isha’ (Night) Prayer or its Adhan (call to Prayer) is being announced. Is it obligatory on me to perform ‘Isha’ (Night) Prayer again?

A: It is permissible for you to shorten Salah during your travel from Bishah to Khamis Mushait. Also, you are permitted to combine between Zhuhr (Noon) Prayer and ‘Asr (Afternoon) Prayer or Maghrib (Sunset) Prayer and ‘Isha’ (Night) Prayer at the time of the earlier or the later ones according to what is most convenient for you, particularly if you speed the travel. It is permissible for you to shorten the four-Rak‘ah Salahs (Prayers consisting of four units) and perform them as only two Rak‘ahs (units of Prayer) in the place where you intend to stay for four days or less. If you are accompanied by a group of passengers you are to offer the Salah with them shortened; but if you travel alone, you should join the congregation (in the Masjid). Shortening the Salah is Sunnah (supererogatory act of worship following the example of the Prophet), whereas performing Salah in congregation is Wajib (obligatory). A Muslim should not leave an obligatory act for the sake of another that is Sunnah. The Salah you shortened before you decide to stay for more than four days is valid. Actually, it is not obligatory on you to repeat the ‘Isha’ (Night) Prayer that you performed at the time of Maghrib (Sunset) Prayer on your journey back home, thus combining the two at the time of the earlier prayer, then your arrival at the time of Adhan for ‘Isha’, because you applied a Rukhsah (concession) granted to you by the Shari‘ah (Islamic law). Additionally, you performed both the Maghrib (Sunset) Prayer and ‘Isha’ (Night) Prayer at the times prescribed by the Shari‘ah for your case.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.