but could the A1 be used like that? say... boot from DVD or CD like a console?
Aye, it could, BUT...
The AmigaOne isnt standard hardware like the A500, A1200 and the like. It doesnt have a built in graphics chipset, and doesnt necesarily(sp?) use the built in audio chipset. Games (and other software) are better off going through the OS instead of trying to support the thousands of audio, graphics and god knows what else chipsets themselves.