I think what the best quest script is really depends on what you want your quest log to look like. All they are is a visual layout for information you want it to show, so it all depends on your preference it seems to me. As for using them, no matter what it is you will need to add a fair amount of information to it. No matter how steep the learning curve, you will eventually need to learn it and the amount of time you spend configuring will be substantial in any case.
To assign call scripts to keys, all you need to do is make a parallel process common event triggered on some switch that you turn ON whenever you want it accessible. In the event, make a conditional branch on key press, choose the button you want (note that buttons do not correspond directly to keys. For the full list of correspondence, press F1 (or is it F2?) during test play), and then inside that conditional branch, put the call script you want. You should also put a few wait frames at the end.