The first step is come up with a simple example of your question. This will make it easier to show how this is done.

Here's a simplified version of your problem:

exampleFunctions = Table[a Sin[a x], {a, 0, 1, 0.1}];
Plot[exampleFunctions, {x, 0, 10}, PlotRange -> All]

How can we run FindMaximum on every function in eampleFunctions? Using Map:

getMaxValue[function_] := FindMaximum[function, {x, 0}]
maxvals = Map[getMaxValue, exampleFunctions]

Note that this doesnt' 100% work for this example. We would have to tweak how we find the max values. Still we can plot these max values:

dataToPoints[{yval_, {x -> xval_}}] := {xval, yval}
maxPoints = Map[dataToPoints, maxvals]
ListPlot[maxPoints]

And naively join the plots together:

Show[Plot[exampleFunctions, {x, 0, 10}, PlotRange -> All],  ListPlot@maxPoints]

It looks like there's variable definitions missing here.

Debugging code is a skill and not an easy one to learn. In the code you attached above you are generating a huge list of Interpolations. Then you are trying to find the maximum value for each of them individually.

If you are having trouble, then do this: Create only one of the interpolating functions. Then find its maximum value. The plot it and it's maximum value.

When you get stuck, step back, find a simpler version of the problem and then work on it.