Here´s my translation. Sorry about the lateness. I´ve been at my parents´ house this week for the fourth, whose WIFI is not working.

•Hann var maður héraðríkur og málamaður mikill.
--He (nom) was (a) man (nom. modern spelling) district-powerful (powerful in his district mas. nom. compar.) and a great (no decl) lawyer (mála-fylgjumaðr).
--He was a powerful man in his district and a great lawyer.

•Þorkell sat vel bæ sinn.
--Thorkell sat (sitja 3. past) well by himself.
--Thorkell kept his farm in (good) order.

•Þau Þorkell og Guðrún áttu son. Sá er nefndur Gellir. Hann var snemma hinn
efnilegasti.
--They (n. nom) Thorkell and Gudhrun had (a) son (acc.). That (loc. mas. nom.), he (conj. masc. nom.) was named (past part or adjectiveÞ) Gellir. He was quickly promising here/there/that? dem. pro. (masc nom or acc.
--They, Thorkell and Gudhrun had a son, who was named Gellir. He was quickly promising.

•Þorleikur bróðir hans var að Helgafelli.
--Thorleik (name? Nom.) brother (nom) of him was to on Helgafelli.
Thorleikur´s brother was at Helgafelli.

•Vel var Þorkatli til stjúpbarna sinna. Guðrún unni Bolla mest allra barna sinna.
Bolli var nú sextán vetra en Þorleikur tuttugu.
--Well was Thorkatli to stepchild his (ply). Gudhrun granted Bolla most of all of his children. To Bolli was now sixteen winter but twenty.
--Thorkatli was good to his stepchildren. Gudhrun granted Bolla most of his children. He had 16 children in winter, but now twenty.