Yes, all of those make a difference. Sometimes a big one.
But in general, it is best to just try to be reasonably sane and not worry about it until you have a proven problem. A surprising fraction of the time, a "reasonably sane" approach is not that far off from optimal. And setting the bar there helps development speed.
Which, of course, is what you care about when you choose to use a scripting language. If you care more about computer time than developer time, then using a more efficient language makes sense.
But in general, it is best to just try to be reasonably sane and not worry about it until you have a proven problem. A surprising fraction of the time, a "reasonably sane" approach is not that far off from optimal. And setting the bar there helps development speed.
Which, of course, is what you care about when you choose to use a scripting language. If you care more about computer time than developer time, then using a more efficient language makes sense.