The way I work is to have black be the areas cut out and white be the wood. Then just make sure you don't have any white islands. If you do, you need to add a bridge to hold those pieces in by painting it in with white. After I think I'm done, or close to being done, I print out my pattern and go over it with a red pen. I circle any problem areas, then go back to my pattern and fix them.
If you're having trouble with a pattern, feel free to post the pattern and the original pic in the Pattern Maker's Lounge. Designers are very generous about sharing advice or offering feedback for your patterns (we have a good group here). Or if you have a specific question, please ask. We'd be glad to help.
That seems like a lot of blades to me. 1/2" oak shouldn't dull the blades that fast. Do you use tape on your wood. That will lubricate the blades and keep the blades cooler. That will extend the life of the blades. That's really the only thing I can think of.