Actually, Lynan, we're on confectioners' sugar, liquid-vs-solid shortening, and now ... sticks of butter!
Really this is an enlightening thread in that the confusions Gobo's dealing with are those we've all dealt with at one time or another, right? It takes awhile to know where and how both to substitute and to eyeball. It's also enlightening how many different ways of measuring still persist despite their flaws.
Gobo, I'm glad it was finally asked "what are you making" since that's crucial to determine how importance accuracy is -- the success of some foods is notoriously dependent on the accuracy of the measurement (cakes, for instance).
However, note that you already got a real big hint that an exact sugar quantity isn't life-or-death in the recipe when they said "3/4 to 1 full box" of sugar. That's quite a bit of leeway ... unless it's a very tiny box of sugar!
As for the shortening/butter/oil issue, in any number of cases you can't interchange solid fats with liquid fats because they behave very differently. Just file that thought away in your head for next time, that you'll want to be sure you can before you substitute. You've obviously gotten away with it here, however, which is great.
I'm going to cast another strong vote for weight measurement, however, and I mean for dry ingredients, wet ingredients, and anything in between! It's much, much easier and far more accurate! Just this last weekend I was making pastry and began measuring out my butter the way I learned as a child, i.e. by the volume/water-displacement method, and then suddenly I thought "hey! I can convert this recipe to weight!" and proceeded to do so. (I've actually always thought measuring solid fats through water displacement was kinda entertaining (little things for little minds) so I'll miss it, but boy is that recipe easier now!)