depends on which lane they shooting and which lane you are
at
how's the traffic condition, any cars block their view
but i got this feeling you did not kenna 
cos not easy to hold steady a speed cam, newbies out of 10
shoots maybe 2 or 3 can register if its hand held ... haha
and furthermore must aim at the number plate, not easy i say
I don't think so. Those days old camera can only shoot 1 lane at
a time. I escaped because I was in the wrong lane along Lornie
(doing 110kmh). That camera can only capture 1 lane at a time. Then
my friend in TP said they have changed to widescope camera, can
capture all 3 lanes.
But TS no need worry if going 100kmh at Tg Katong, that one is
90kmh if I'm not wrong, so plus minus 10-15kmh, they usually let
go. Plus your speedo not very accurate if show 100kmh might
actually be somethng like 97-98kmh, still quite safe. Just be
careful where the signs say 80kmh, that one you drive 97-98, high
chance will kena.