I've been struggling to upload so I'll post info on the next post...
Just wire up the gates on the grid, and pick "simulate", if you have a clock in the system, the lines will be black (low) or green (high). If the design isn't clocked, it behaves as a state machine, only responding to input changes (such as switches). If it simulates and produces the output you want, then the design is logically sound.I've just downloaded a copy of logisim and am currently inputting the same circuit into it, to see what I can find out.
What particular process should I run in order to give you some useful information?