First off, you really have no way top test the signal strength of the signal coming in, That takes fairly special gear ehich, AFAICT, only their people have access to. Not that you can't buy it somewhere, but it's not really economically feasable, and then there's the little matter of learning how to use it.
Second, that's a lot of splitters in your house! Remember that a digital signal is more "forgiving" of signal glitches. Considering you're depending on an analog signal which can vary somewhat from day-to-day, I'm surprised you get as clear a signal on all those sets as you do. It's not expected to drive too many sets.
But, the upside of analog is that you don't need special equipment to get it over cable (dunno about next year, though) because your TV's internal NTSC tuner can receiver it and you can easily split the signal as many times as you can get away with.
Now, when you go satellite, I think you're gonna need a set-top-box for each TV you connect to it. Your TV's internal tuners don't work for satellite or any digital signal, except perhaps for unscrambled cable digital signals if your provider allows that and you have a QAM tuner.