"Am I just too distrusting of thieving scum? Wouldn't be leaving some of them in the middle of Leeds all day."
NO!
belive a lot of these poster's just dont seem to get it!
round my way anyof those would be diassembled in no time.
you need;
no brand names.desticker it (even if its crap)
no names on components.paint over or scratch off (snobbery wont do you any good when your walking home)
puncture proof tyres.
no quick releases.change them for bolt in.(inc the seat)
matt black aerosol can do wonders when applied in abundance.
huge lock or …two huge locks.
lock it somewhere very public and lit at night.
if all else fails fit drop bars..then no one will want it 😆