If you never do an assisted or paddle-float reentry then deck lines are not necessary for your "safety". If you never need to grab your boat anywhere except at the cockpit, you can do away with bow/stern handles.

If you ever do an assisted rescue for someone else, or even raft up with someone, deck lines are VERY helpful. It can be a lifesaver if someone else can get a grip on your boat. Also, if someone ever assists you in a T-rescue, deck lines will really help them grabbing, controlling, and flipping your boat.

If you need to grab your boat at a weird place (Surf landing, for example, or getting out on a floating dock 2 feet above water line in waves - once you're out of your boat you want to grab it quick) then deck lines & hand grips near the ends are really helpful.

So if you're only going to be launching/landing in calm water, you always paddle solo, and your roll is bombproof, then you can probably skip the deck lines. Otherwise, I highly recommend them.

Bungies - I'm not using them as much now that I have a day hatch and foot-operated bilge pump, but I still stick a chart under them, often carry a spare paddle, and use 'em as a paddle park.

Val