So I'm trying to figure what the benefit to make my own ROM would be. Does it free up storage space by storing the programs somewhere else? Basically would I really see any benefit from loading my copies of SPB Weather, SPB Diary and other programs in the rom?
Yes, by incorporating them into the ROM they don't use your storage memory. But the catch is that they have to be able to run properly from within \Windows. If you need to move files to any other folder they will end up taking storage memory.