Now they have just got better with an above inflation pay rise and extra increments to the basic salary
Except that the pay rise wasn't above inflation as it won't be backdated to October. It's effectively below RPI for the first period and RPI for the second period.
Would it not be better for your cause, to set up the trolleys when it is safe to do so, just work efficiently yet calmly and if a third of the passengers don't get a drink and snack, TOUGH!
The problem with your approach is that it is safe to do these things. LGW do them, other airlines do them. It's only LHR that don't want to do them, not because it is unsafe but because it's too much like hard work.