I think the sutures / needle suggestion is a very bad idea. Wounds can be hard to clean and obtaining a sterile field is problematic. When a contaminated wound is closed with sutures it creates a perfect environment for sepsis and gas gangrene. Lacerations caused by marine shells, reefs etc are very difficult to clean thoroughly, and many physicians feel it is especially problematic to suture them. Far better to clean it well, apply a sterile dressing and bind it closed until professional care can be obtained.
Think about where you're paddling. Is it a very remote expedition where help is days or weeks away? Not likely. Most outings are day-trips and medical facilities are relatively close at hand. Stock your kit accordingly.
You'll get a lot more use out of an assortment of band-aids, gauze pads, a wide roll of bandage adhesive, a couple of "ACE" bandages, antibiotic ointment, and "moleskin". Good bandage shears also come in handy - the ones with the safety nub on the lower blade are nice. Tweezers are good, too. Betadine antiseptic solution for cleaning around the wound area is good. I've used hydrogen peroxide to irrigate small wounds and abrasions. Sterile water for irrigating a wound is also good.
Sunscreen, lip balm, a sealed flagon of grog - all these come in handy...