VRAM is video random access memory, meaning any RAM primarily used by a video chip. CHR RAM is a type of VRAM, usually 8 KiB in size unless bankswitched.
Which also includes name and attribute tables, OAM and palette memory.
True. But in practice, OAM and the palette are part of the PPU chip, not discrete components visible on the external bus, and not part of what is normally called "VRAM".
Yeah, this is true as far as the NES is concerned. Some other video chips though, such as the TMS9918, use the same memory for everything, so there is no guilt in calling everything VRAM. I'm not sure which setup is more common among the various video chips.
A lot of graphics architectures put the display list (called "OAM" on NES) and palette in a separate address space from the big VRAM, as it keeps the sprite hardware and color lookup hardware from stalling VRAM reads by the rest of the system.
Among systems for which I've read the technical specs:
Palette memory is separate from VRAM in NES, EGA, VGA, GBC, GBA, and DS, except in the DS's "extended palette" mode with 16 palettes of 256 colors each and in the DS's 3D mode.
2D display list is separate from VRAM in NES, GBC, GBA, and DS.