Jay,
I generally believe that Show is not a good approach for this. I would use Epilog to add annotations to plots.
Manipulate[
Plot[myIndicatorFunc[-2, 5, x], {x, -10, 10},
Epilog -> {Directive[PointSize[0.02], Red],
Point[{y, myIndicatorFunc[-2, 5, y]}], Directive[Blue],
Text["point: " <> ToString[{y, myIndicatorFunc[-2, 5, y]}], {y,
myIndicatorFunc[-2, 5, y] + .05}]},
PlotRangePadding -> Scaled[0.1]], {y, -10, 10, 0.5,
AnimationRate -> 5}]
I used Epilog with Directives to set the style for the point and the text. I used PlotRangePadding to give extra room for the label as it moves around. I changed the animation from 1/2 to 0.5 because Mathematica tries to use fractions which do not turn into text very well (i.e. 5/2 vs 2.5). With Epilog you can pass a bunch of plot annotations.
I hope this helps.
Regards,
Neil