Funakoshi (if this is your name?),

If you find ways to improve it - please go for it!
I really think competition between different miners is a good thing. Furthermore I believe that dev fee is something totally acceptable - if the dev fee is worth the performance and stability. The market is big enough and great and reliable miners will always find plenty of rigs to mine on.
Finally I wouldn't focus too much on Windows. No serious miner (with more than really small number of rigs) will use Windows, because its hell to maintain and never stable as a Linux system...

Cheers,
Andy