Since you haven't changed the EBOOT run address (0x80040000), no change was needed for ROMOFFSET.
But in your change, your RAM (RAM 80150000 00120000 RAM) had cover the address 0x80200000, this address is the WinCE NK running address, that means EBoot need load NK.nb0 to it, but the EBoot itself had used this address, that will be problem, your will fail to boot the NK.
I think the simple way is just keeping the default eboot size, and put your "picdata.h" to binary file, and use some reserved SD sectors to store it. And when the eboot wants to show it as boot screen, it can read the data from SD card to framebuffer.