If there was some way to make use of board formats other clients use, you have several right away. You wouldn't need permission to use them, as you are not shipping your product with them.
If it is not directly possible to do that, maybe an import function could be created, or a separate translator.
Make everything as standardized as possible, e.g. import/export match formats widely used.
Where possible, import profile/config info from other clients. Do you support the profile field that javafibs uses for country/gender etc...?
You might also want to update the name of the webpage
No license? Is this program in the public domain? Am I free to redistribute it myself for fun and profit? Am I able to reverse engineer it?
Your web page doesn't make it immediately clear that this is a windows only client. Which versions of windows will it run on? Would it run using wine on linux? What about that Mac thingie that allows those nerds to run windows apps?
Any chance of the code being made open source? The one thing that fibs lacks is a first rate open source client. I doubt you would make money with this thing anyway, not because of any lack of quality, but there are already a sufficient number of options for fibs freeloaders.
BTW, what promise do I get that this thing does not install any malware on my windows box?
What about proxy support? That might be a feature that would set you apart. Most clients are not socksified.
Screenshots look great. I'm just trying to give you lots to think about for 1.0.
Nice work and good luck!