Be cautious around fresh water algae-covered stone is even slipperier there than close to the sea.
Your footwear should provide very good traction. Consider wearing gloves to protect your hands. The boardwalks have astonishingly aweful sections with nails poking up to snag your feet. It is hard to believe this hike is allowed.
If you do fall, often the best strategy is to turn so that you land on your pack. This will cushion the impact -- but you may suffer the indignity of being turtled (trapped on your back). Try to get back on your feet before anyone has time to take a photo.
Theres a chance youll be hurt by trying to prevent a fall. If you think you might fall, go with it but fall as safely as possible. Draw your hands in to your chest as you fall to reduce the chance of injury to your arms.
Scrapes & bruises are almost unavoidable. The scramble along Sandstone Creek may be the most difficult section of the West Coast Trail, arguably more difficult that the surge channels.
The Soggy Bottom Boys kept a Slips & Falls scorecard in 2005 all 4 hikers had many.
Heights? How difficult are the ladders?
Difficult! Especially if you have any kind of a fear of heights.
We've heard a rumour that a woman had fallen in 2000 when a ladder rung came off in her hand but we've never had that story substantiated.
One of our hikers has a lifelong fear of heights. It was a big challenge for her to face the ladders, cable cars, & suspension bridges on the West Coast Trail. Walking fallen logs over ravines was even more intimidating.
She overcame her phobia and hiked the WCT twice in 99. (Others have turned back on reaching the first ladder, however.)
On ladders we strongly recommend you practice 3-point-climbing. Be sure that you have a good grip on the rungs before moving a hand or foot.
Be smart. If you are worried about the ladders consider planning to have stronger climber(s) carry your pack up & down for you. It's much easier to climb without a pack.
Take your time. Rest leaning your pack on the railing. There are many chances to sit down on platforms without removing your pack.
There are a lot of ladders on the WCT. Karen Sykes counted about 50 ladders & 100 bridges. (The exact number depends on your route if you stay on the forest trail you have more ladders than if you stick to the beach as much as you can.)
The highest ladders are on the south side of Cullite.
The ladders are not nearly as slippery as you might expect, even in the rain.
No more than one climber on a ladder at a time, please -- just in case a water bottle (or something) falls off a pack on to the hiker below.
The suspension bridges and cable cars are easier than ladders for most hikers.

Pack weight pulls you away from the rungs.