Fair enough. So in answer to your question, there are no fixed rules as to where to place the joints or the ballast for that matter. But, if you are going to use a lip to drive the action, then it will need to sit in the water slightly nose down.
As for the lip angle, around 70deg if you want it to swim the surface, decreasing the angle to go deeper. Even this is not a hard and fast rule, as you can make a 45 deg lip swim shallow if the lip has a smaller area.
Like developing any new design, be prepared for a period of testing. The sucessful end result will be a combination of lip position, lip angle, lip size, tow eye location, ballast position, etc.
As for the hinge locations, a good place to start would be to scan the photo library and see where everyone else puts the joints.
Rough out a few bodies and accept that these are for testing only, so no fancy paint schemes, just seal them and paint white, for visibility. Go to the lake with lip material, super glue and a few tools, for on site modifications. I bought a battery dremel for the job, excellent!
I've just read what I have written and realise I have not really helped much. I hate saying trial and error, but that is the way it works. What I will say, is that you can cut down on future blind trial and error, by keeping notes of each adjustment, cause and effect. Eventually, you will get a "feel" for the lure. Secondly, only change one parameter at a time, or you won't know which change worked and you will have to repeat the tests.
Good luck with it and let us know of your progress.