jim....I have sympathy with your views and your argument. But even in the safest seat, there is never 100% voting for the winning candidate.
Take Liverpool Walton, currently Labours safest seat ::::
http://en.wikipedia.org/wiki/Liverpool_Walton_%28UK_Parliament_constituency%29#Elections_in_the_2010s
The seat was won by Steve Rotheram with 72% of votes cast. If we leave out most of the fringe runners up, the LibDems and the Tories comprised the other 21% of votes. How would any new voting system offer the constituents of Liverpool Walton a better result than they have already got ? They quite clearly voted for Labour.
At what percentage below the winning 72% in this seat, would another system offer a better result ?
I realise that I have deliberately chosen the toughest test for any PR change, but there are lots of seats like this, for Labour and the Tories, all over the country.
FPTP is simple to understand, but none of the alternatives have that advantage.
The people know exactly who is representing them and why.
KISS....Keep it simple stupid would seem to win the day here.