british etiquette

I have never personally worked in the food service business, so I am a bit unsure as to how the entire system of payment for waiters and waitresses works in relation to tips.  However, things get even more inscrutable here.

In America, tips are not usually required for the bill.  Fast food completely omits the obligation for tips.  Otherwise, the generosity of the tip is a direct reflection of the service quality and the tipper's disposition.

In England, the tipping game is a bit of a free-for-all.  Usually the tip is included in the bill.  When it isn't, you might get any sort of notification from a reminder on the receipt to a small addition to the fine print at the bottom of a menu (these places are betting that hungry customers are much keener than I would imagine!)
Those times when it is not included and requested, I always raise an eyebrow.  So then, where is the money going for my fourteen-dollar (approximately) burger?  The VATs (value-added tax, I didn't know that til just now) can suggest sums as much as 20% too!  Shockingly (to an American), Pizza Hut was asking for a 20% tip.  How often do customers actually grant them this much?

Secondly, the fact that the tip is usually contained in the regular price gives the waitstaff a certain liberty to let their personalities and moods govern their customer relations.  I expect that I am being a bit stuffy and stubborn, spoilt in America where customer is king, however I am a bit indignant when I have to actively flag down a waiter for a bill after 15 minutes of pushing my plate away, or when orders are mysteriously forgotten or bungled.  Also on my list of negative dining experiences: unhelpful, exasperated, or unfriendly staff (or staff that decide to simply take breaks from paying attention to customers for 20 minutes but continue to stand at the cash register,) dirty dishes, peculiar aromas, and an aggravatingly frequent tendency for everywhere to be out of stock of several staples.  (One bar was completely out of Bailey's when 75% of their cocktails required Bailey's, while McDonalds had inexplicably turned off their ice cream machine in the middle of the day.)  Such things would be considered embarrassments for the establishment in the U.S. -> when we would run out of half-and-half for italian sodas at the movie theater where I worked, "We're out of that" had to be preceded by "I'm terribly sorry."

I suppose these things are normal here.  In truth, I'm a bit of a self-conscious traveler, so I often wonder if I am being taken advantage of because there is little hope of us Americans being regular customers, though this is a bit of a paranoid approach.

This is definitely a learning experience.  At the very least, I'll appreciate the promptness at McDonalds exponentially more.