Frost, I admire your guts to start a project like this which will be very big an complicated.
From a business-plan point of view you'll might have to look at the position your project will take amongst the alternatives. Who are the target audience and why would they go for your solution instead of the existing ones. Or, IOW, why re-invent the wheel, as someone put it.
As I see this thread developing, ppl using complex powerful languages are already supplied and are unlikely to change. The audience that is still somewhat unlocked are those currently looking at maybe Amibroker, using QT for charting and some trading front-end, like Buttontrader or Ninja.. Several mentioned the paintbar tool in QT and I would predict that if Medved Jerry decided to implement not only paintbar alerts, but also an autotrade trigger along with that, many will be groping for it as the final solution to their problems. This would make your project, however ambitious and fun, a bit obsolete.
The one thing that isn't there and with which you would fill a gap is a true open-source solution, built on a portable engine so it runs on other platforms as well. If you could reformulate your role as programmer to that of open-project developer, you'll be amazed at the help you'll get and the quality of the knowledge available. This then would become a thing with a true future for which some would be willing to pay with something more valuable then money, their time.
I don't exactly understand you 'proprietary' argument. These are not trading related, am I right? If they are coding-related I would find it curious if you'd have thought of coding-solutions that are not already out in the open. But maybe you have.
Anyway, I whish you the best with you project, but please take a closer look at it's selling points.
Ursa..