Two things come immediately to mind. The first is that, while it is inadvisable to run 2300W on a 2400W
circuit unless it is specifically designed to do so, you can, very likely, run 2300W of lights at 80% on any 2400W
circuit for a very long time.
Second, while you are quite limited in your
power, you should think of this in terms of the maximum amount of
power you can draw AT ANY ONE TIME. You can hang substantially more lights than you have
power available if you take care not to put them all on full at the same time. While this may sound a little crazy at first, it means that you can create a number of different looks, with different instruments, allowing a lot more variety to your shows than you may initially believe (you could have a set of lights for a daytime look, an evening, indoor look and an outdoor look with a strong moon light, each using all of your available
power (and, likely, mixing some of the instruments).
With all do respect to the big shows (they take their own
level of capability), it takes much more thought, care and creativity to do a lot with a little than to do a show with everything you ever dreamed of having.
With regard to your S4 question, both the S4 and the jr are fine instruments. However, I cannot think of a situation that a S4 Jr. with satisfy that a full scale S4 will not. On the other
hand, there are many tasks that a full size S4 with do that a Jr. will not. If you have the budget, I would strongly suggest the full size S4. Finally, I have a couple of S4 Jr zooms that I really like. However, I would advise against buying zooms for most theatres. If you
pick up S4s on the used market, you can always buy different
lens tubes to meet a specific need. As you have very limited hang points, I don't think you will need a very wide range of lenses.
Tim.