If you want to add a menu shortcut for that you can easily do so by editing this:
FrontEndExecute@
FrontEnd`FindFileOnPath["MenuSetup.tr", "PrivatePathsTextResources"]
Maybe change this:
MenuItem["Evaluate Notebook", "EvaluateNotebook"]
to this:
MenuItem["Evaluate Notebook", "EvaluateNotebook",
MenuKey["Return", Modifiers -> {"Shift"}]]
However, if you're going to be modifying your program often, I'd suggest turning it into a collection of functions, each doing a small thing, and working that way. This is the best approach for larger scale work.
Notebooks are great for linear explorations, reports, small-scale iterative testing, etc. but if you need to change parameters often that will flow through to other calculations, it's best to take a developer point of view.