1) yes, same thing. I think years ago a turf race was represented by a single dash, but at some point that changed to two small dashes. Guessing it may have been a change to the database or such.
2)That indicates a negative number. A 1—-is faster than a 0, a 2—-is faster than a 1––, etc……
3)Same as #2. Seems redundant, but maybe it’s meant to ensure it stands out. A negative zero and a quarter on the turf —-0 with a superscript 1 followed by another —-(can’t do that on my iPad) might be a little confusing.