The reason I use a fluro carbon trace is because it makes the line invisiable to the fish. You can get a decent trace line for around $15 and it will last you for months (depending on how you fish that is).
I find a metre trace allows the bait to appear "more natural" in the water. My experience has been I have a better chance of a bite with a trace this long.
Regarding the beach, it really depends. Once you know how to identify a gutter, your catch rate will improve as this is where the fish sit. I love beach fishing but I am still only learning the ropes myself
With Maroubra beach if you park at the North End you are slightly elevated and get a good view of the beach, I normally identify the gutter from there and then head down to my spot.
If you have any further questions fire away and I will do my best to answer them
gav