> Hann var sonur Þorgeirs gollnis Þórólfssonar.

The nominative singular would be 'gollnir', masculine long ja-stem
like 'hersir', 'hellir', etc.

> Skógverjar

Magnús Magnússon & Hermann Pálsson: "the men of Skogar"

> skorargeirs.
> 'Spear of Notches'

skorar, genitive singular.

> sá hlutur var á ráði hans
> (how to tell whether it was his lot or his choice (plan)?)

MM & HP: "he had one peculiarity". I think it must be involuntary, a
condition rather than a plan. Zoega: 'ráð' (7) "state of life,
condition, lot". Hallgerðr later makes a lot of this later when she
wants to be insulting, e.g. to Bergþóra in Ch. 35: Þú hefir kartnagl á
hverjum fingri en hann er skegglaus. "You have a diseased nail on
every finger and he's beardless." Compare also Þorsteins þáttr
uxarfóts: Þó var mikill mállaki á ráði hennar. Hún hafði ekki mál og
var með því alin. "However she had a serious speech defect. She
lacked the power of speech and had been born like that." Looking on
Google, I found a similar expression current in Icelandic: sá var
ljóður/brestur á ráði hans "he had this fault"

http://digicoll.library.wisc.edu/cgi-bin/IcelOnline/IcelOnline.TEId-idx?type=entry&eid=RA1D1&q1=r%E1%F0

> á leigustöðum.

MM & HP: "out on loan"

> og þótti mönnum því það ráð að þeir þreyttu það ekki með sér

MM & HP: "and he was persuaded not to try to fight it out." More
literally: "and men thought it advisable therefore that they didn't
disbute that [matter] between them." See Zoega 'ráð' (4) "wise
councel, what is advisable".

> Enda er sá engi minn frændi að gangi í þetta mál ef þú hefir eigi

þrek til.

MM & HP: "There is no one else in my familiy to undertake this claim
if you haven't the courage for it."