I have some experience here, I used to work on C41. First of all why not just submit to a lab, you will get a better result and you can scan post process even if the fog is higher than normal, low contrat films are better for scanning, you can correct with levels etc in PS. Secondly the colour developer is oxidised and reacts with the film coupler to form the image dye, the silver is converted back to silver halide by the bleach and then removed by the fixer. So like the other guy said do not bleach it if you are using a B&W developer. If fog is likely to be high due to poor storage a milligram or two of benzotriazole per Litre will cut the fog, but you might lose some detail in the toe of the film curve, thats shadows on the print.
The orange mask is to correct the unwanted absorptions in the film dyes a sort of anti contaminant of the image dyes. It is only required if you are going to optically print the film, you can get away without it in B&W, and anyway you will convert your black and White image to grayscale probably.
