Here’s my translation

Alan

Þá fóru þeir í Selárdal ok váru þar nökkurar nætr. 
Then they journeyed to Selárdalr (Shieling-River-Dale) and were (stayed) there several nights.

En er þeir fóru heim, þá fundu þeir Árna á götu, ok hjó Loftr þegar til Árna, en hann bar af sér höggit. 
But (And) when they journeyed home, then they met Árni in [the] way (as in he was lying in wait for them), and Loptr hewed at-once at Árni, but (and) he warded off (lit: bore from himself) the-blow

Síðan sótti Loftr at honum, en hann varðist vel. 
After-that Loptr attacked him , but he (Árni) defended-himself well.

Ok er Galta þótti Lofti seint sækjast, þá fór hann til ok vann á Árna, ok síðan vágu þeir hann. 
And when [it] seemed to Galti to advance slowly for Loptr (ie that Loptr made slow going of it), then he (ie Galti) went towards [him] (ie Árni) and did Árni a bodily-injury (<vinna á e-m>, Z12), and after-that they slayed him.

Þat víg varð inn næsta dag eftir Óláfsmessu.
That slaying happened (<verða>) on the next day after Ólafr’s-Mass.

Þat víg mæltist illa fyrir, því at fé öll höfðu goldin verif fyrir Árna ok hann hafði sætt þá, er ger hafði verit á hendr honum, vel haldit við Loft. 
That slaying was ill spoken of, because all monies (ie fines) had been (typo <verið>) paid for Árni, and that agreement, which had been arbitrated (<ger> pp of <göra>, Z10) against him (<á hendr e-m>), he had well observed (hafði…vel haldit) respecting (or, perhaps, in conjunction with?) Loptr.

Síðan bætti Loftr frændum Árna fé, sem gert var á hendr honum af þeim mönnum, er til gerðar váru teknir.
After-that Loptr paid weregild to [the] kinsmen of Árni, as was fixed (arbitrated) against him (<á hendr e-m>) by those persons (men), who were chosen for (<taka til e-s>, Z12) [the] arbitration (<görð>).

Loftr bjó nökkura vetr á Rauðasandi síðan ok varðveitti bú bræðra sinna, til þess er þeir höfðu aldr til at taka við fjárvarðveizlu sinni.
Loptr dwelled several winters at Rauðasandr after-that and kept [the] farms of his brothers (plural), until they possessed (ie reached, <hafa e-t til>, Z14) [the] age (ie were old enough) to receive (ie take over) management-of-their-own-property.

8. Frá Vatnsfirðingum.
8. About [the] Vatnsfjörðr-folk.

Maðr hét Snorri. 
[There] was a person (man) called Snorri.

Hann var Þórðarson, Þorvaldssonar, Kjartanssonar, Ásgeirssonar, Knattarsonar. 
He was son of Þórðr, son of Þorvaldr, son of Kjartan, son of Ásgeirr, son of Knöttr.

Sigríðr hét móðir Snorra, dóttir Hafliða Mássonar. 
[The] mother of Snorri was-called Sigríðr, daughter of Hafliði Már’s-son.

Snorri var höfðingi mikill, ríkr ok fjölmennr, vitr ok stórráðr. 
Snorri was a great chief, powerful and with-many-people, wise and ambitious.

Snorri bjó í Ísafirði á þeim bæ, er í Vatnsfirði heitir. 
Snorri dwelled in Ísafjörðr on that farm, which is-called in Vatnsfjörðr.

Snorri var lítill maðr vexti ok vænn at yfirliti ok vel vaxinn. 
Snorri was a small man in stature and handsome in appearance and well grown (ie fully grown up)

Hann átti margt barna, ok váru engi skírgetin.
He had many children, and none were begotten-in-wedlock

Hafliði hét sonr hans. 
His son was-called Hafliði.

Hann var vitr maðr ok vinsæll ok mikill umbótarmaðr, bæði með föður sínum ok öðrum, þeim sem hans ráð vildu hafa, því at Snorri þótti eigi í öllum stöðum jafnaðarmaðr vera, en sá ójafnaðr gekk aldri við, ef Hafliði var nær, fyrir gæzku sakir hans ok réttlæti. 
He was a wise person (man) and popular and a great mender-of-matters, both with his father and others, those who would have his counsel, because Snorri was-reckoned not to be an impartial-person (man) in all respects, but (and) that unfairness (<újafnaðr>) never went by (ie prevailed, stood?), when Hafliði was near, for reasons of his goodness and righteousness.

Af því var hann vinsæll við alla menn, at hann vildi öllum gott.
He was popular with all persons (men) from that, that (ie because) he wanted good for all (ie everyone).

Þat var einu sinni, at einn vinr Snorra ræddi fyrir honum um vinsældir Hafliða ok tjáði þat, hversu gott höfðingjaefni hann var.
That was one time, that a certain friend of Snorri spoke (<roeða>) before him about [the] popularity of Hafliði and related that, how he was good chieftain-material (the right stuff).

Snorri svarar: "Engar nytjar munu menn hafa Hafliða, því at hann er miklu betr at sér um alla hluti en ek sé verðr at njóta hans.
Snorri answers: “Folk (men) will derive no benefit from Hafliði, because he is much better in himself (ie a superior person) concerning all things than (or and/but?, ie <en> Z1/2, or Z3?) I would-be worthy to derive-benefit from him (Not sure what this means?).