.. anyway! - I've been busy working on iTrader to give it more use and v2.0 is here!
check out here to see all the updates!
* feedback appreciated!
Actually - you may not need to release the source to the general public. Why not bring a couple of other developers in and just trust them with the source. I for example would be all about adding a framework for adding multiple exchanges and building an arbitrage mode into the trader.
The other thing you could do potentially do is turn this software into a pay over time subscription based online engine. Maybe the risk would seem less if they had to deposit to an account on a server instead of having unknown code running on their personal machine. Granted you'd have a huge overhead in securing the site and associated costs... but it might be one direction to go.