Manipulate objects.

One of my responses has JS array that you display wrong in the ui as key:[{ object }]
I think it would be great to see the object in the Output section and what would be even awesome would to let me manipulate the project with a subset of javascript (perhaps on Rhino).
For example by array had values [1,23,4,556] and I would like to create a new virtual value that basically is the sum or the average of this array. 

It would be also great if you could offer a lookup function in a key/value store so that I could replace some value in excel style functionality. I think you build a lot of excel type macros into the product.