-- Last Updated: Feb-07-13 9:38 AM EST --
Your particular kayak is perfectly fine for taking out in the ocean. It is not as fast as longer sleeker kayaks, but it is more stable without being a barge. Has 2 bulkheads and a decently sized cockpit that allows easy re-entry while not being too big to be hard to protect well with a skirt. The lack of skeg might make you work harder in winds, but because of the short length of the kayak, unlike with longer kayaks, you will likely not run into too much problems trying to control where to go in strong winds. But, you have to try it in controlled conditions to make sure you can manage it.
You can roll it, you can re-enter it, etc. like any other "real" (non-recreational) kayak.
Does not have perimeter lines but has lots of points to hold on to. You can add a line between the rear carry handle and the rear bungies and similarly on the front. Or if you like install full perimeter lines - paddling stores sell the necessary hardware and it will cost you probably only $20 bucks or so.
Shorter boats like this can be a lot of fun in shore break and short-period steep waves.
I paddled for a couple of years a Perception Sonoma 13.5 and (other than the lack of a front bulkhead) I did not feel I was missing much compared to longer kayaks. I did add a line between the bow and the cockpit and I did not need that in the rear as the stern is so short and there are already bungies there for storage and can hold onto them if needed or the rear handle. I mostly paddled it in rough water but it goes without saying it was fine in the flat too. That was 22.5" wide so not as stable as yours and very fast for its length but otherwise probably a similar experience...
So, if you can handle the conditions, this particular boat of yours will not be an issue for general use.
Oh, and flat bottom and wide beam does not automatically equal unstable in waves. If the paddler skill is lacking, a wider boat will be much safer for them than a narrower one with a rounder bottom. Some of my white water kayaks (say Axiom 9.0 at 27.5" wide) are wider than the OP's boat and with just as flat bottom (the Axiom is as flat as they get, for surfing and planing). Yet I have not heard anyone say that they need a 19" white water boat for added stability in rough water - just the opposite. You will find that WW boats generally have a LOT more stability than most sea kayaks because they need that stability in rough conditions; they are very similar in stability to rec boats, in fact. The key is to let the boat move with the water and to not be afraid to capsize from time to time...
All of the above - my opinion, so take it as that and it might or might not hold water for anyone else's situation :)