Can I have a name other than iwannabeapirate, I feel too silly calling you this.
Now to answer your question, it keeps really well on the shelf. Usually lasts (the DH uses it and me for cooking) about 12 months without any problem whatsoever.
I don't process it, as you said the vinegar is acidic enough and the original recipe came from a pickling book that none of the pickled foods are processed. I've done a few of the recipes and everything has kept very well but you need to ensure you use the correct amount of the vinegar to veg ratio (in the pickled veg recipes).
With you liking fish, the original worchestshire sauce has anchovy it. I've seen a few recipes around that use anchovy.