I would add one more use for suppressors: training. While I am not a certified trainer (by any stretch of the imagination), I could easily see that suppressed rifles would be useful in training young shooters. The reduced noise would allow them to develop trigger control without developing the flinch that comes from the much louder (unsurpressed) bang.
I'm a lawyer, but I'm not your lawyer. If you need some honest-to-goodness legal advice, go buy some.