Remember: As soon as you install a graphics board, you can nolonger use Deluxe Paint.
Sure you can, a graphics board does not prevent the native chipset from being used, just hook a video monitor to the native output. Deluxe Paint 5 also has an RTG mode, which is far from perfect, but it helps a little if you want to run it on RTG display.
Also, you do not need a graphics board for MagicWB. It looks great at 640 X 400 resolution. You do need a Commodore A2320 Amber board, more important then a graphics board in an Amiga 2000. MagicWB only uses the standard 8 colors of Workbench.
Eh, and? There's no problem using MagicWB on graphics board, people even use MagicWB icons on MorphOS and OS4.
Amber is only important if you want to use OCS/ECS with a VGA monitor, nothing that blakespot has posted suggests that he has that need, he just want MagicWB on his PicassoII from what I can read.