You are using BusyBox which does not support the full command set for the cut utility.
Change this line:
TORRENTLIST=`transmission-remote $SERVER --list | sed -e '1d;$d;s/^ *//' | cut --only-delimited --delimiter=" " --fields=1`
to this:
TORRENTLIST=`transmission-remote $SERVER --list | sed -e '1d;$d;s/^ *//' | cut -s -d " " -f 1`
All you are doing is replacing:
--only-delimited --delimiter=" " --fields=1`
with the busybox equivalent
-s -d " " -f 1`
Hope that helps!