Heill Dan!

A very good translation indeed.

The most difficult sentence is probably the one
Simon was wondering about.

> Þetta þótti mörgum manni vanhagr mikill, sem
> var, at sitja um þat fram er markaðrinn stóð.
>>
> Many men thought this a great disadvantage,
> which was, to tarry from that time forward when
> the market stood.

I'm not absolutely sure myself, but I'd translate:

"Many a man thought this to be a great disadvantage,
as indeed it was, to stay longer than for the
duration of the market."

Note that in 'um þat fram' it is 'um fram' that is
a single unit meaning something like "exceeding".
We could also have 'fram um þat'.

Under the 11th meaning of 'um' Zoega gives:

- - - - - - - - - - - - - - - - - - - - - - - - -
um alla menn fram _or_ um fram alla menn,
_above all men_ (hón unni honum um alla menn fram)
- - - - - - - - - - - - - - - - - - - - - - - - -

http://www.northvegr.org/zoega/447.html

It's THIS that's difficult in learning languages ;-)

Kveðja,
Haukur