> enda á (eiga) eg Njáli marga sæmd (soemd) að launa (is this in

respect of past deeds or for the present insult?)

> moreover I must pay great redress to Njál

I would have thought it just means that he's indebted to Njal for all
the help that Njal has given him in the past, and the friendship that
Njal has shown him, rather than that he now needs to make up to him
for this insult or "pay great redress".

> Líður (present tense) nú á sumarið og allt til þings framan.
> and went home to Hlíðarendi and was (stayed) at home all through

that winter. (It) passes now to the summer and completely forward to
(the time for the) Thing.

'líða á' (of a time period) "to draw to a close", impersonal with the
time period in the accusative. Zoega has the examples: 'er á leið
daginn' "when the day was far spent"; 'um hausit at auliðnu' "late in
the autumn"; 'at áliðnum vetri' "late in the winter".

But 'líða at e-u' "to approach, draw nigh", e.g. 'er at leið jólunum'
"when it got near to Yule".