jamaat salaah

What should a masbooq recite when standing up for missed rakaats?

Q:

1. Suppose I am offering Asar or Maghrib and I joined the Namaz in the last Rakaat after missing the first three rakats, now when the prayer ends with "Assalaamu alaikum warahmatullah" by Imam and I get up from "Attahiyyaat", Then what do I have to say first? Do I have to start my next rakat with thana or bismillah?

2. Also, do I have to say a surat after reciting surah fatiha?

Pulling a person back from the front saff in Jamaat Salaah

Q: If a person comes last in the masjid and there is no space in the first row

1. Should he slightly pull a person from the first row to stand next to him?

2. If the person from the first row comes back to join the person standing alone in the back, what should be the duty of the men who were standing left and right of the person who went back? Should they remain in their places or move closer? What is the proper way to fill that space?