My boss's scorpion has a rear single post with a ski eye welded to the top,it carries a nav light and vhf antenna too, it's stainless.
The problem about wrapping stainless in carbon is once you add salt water you get reaction issues. I would go for a stainless option, if it is sunk into the floor and held as high as possible with a support collar is will be strong enough to tow.
As far as the strength of this one, I will clamp to the bench and hang some lead ingots from the tip to see how strong it will be. The tube is rigid and the glue is as strong an the tube if not stronger, so I think it will cope with being used as a handle!!