To my knowledge no imperial faction or sub-faction contains Sonic weaponry such as the ones that the Chaos Sound Marines use and there is no mention of them in the Horus Heresy books (Though I've only read as far as when they're trying to get a message back to earth about Horus' treachery) So is it possible that since no sonic weaponry was used pre or post heresy by imperial forces that the Sonic Cannons are a possible mutated or daemon weapon? Discuss.
The Sonic Weapons were invented by the Emperor's Children after Istvaan V. There is no imperial counterpart to this technology. The first Noise Marines were born during the Maraviglia, a concert/Chaos-ritual that happened on the Pride of the Emperor just before the Dropsite-Massacre. The first versions of Sonic Weapons were used during the Dropsite-massacre and were basically just modified musical instruments (see novel Fulgrim) and later on better versions were developed (see novel Angel Exterminatus). It is rumored that the Dark Mechanicum aided them in creating these weapons (Dark Heresy: Radical's Handbook p.120).
Most likely, but chances are the mechanicus would snatch it up if you found it and push you guys out the door with out so much as a thank you.
By that you mean they would actually keep you there, Chem Geld you, and then force you to work to death in a labor camp.
