I would only change some minor things,
No1 have a 1.78mb High Dens Disk supported and standard in the A1200 & A4000
No2 have a FPU chip at least 68882 - 20Mhz on all AGA range
No3 have a A4000CD edition launch mid 1993
No4 have Team17 or another developer make a game to show off the AGA, FPU and general power of the Amiga.
No5 port Doom to the Amiga, even if it only could run on the A4000 I think we needed it back then to prove the Amiga could do a game like it as many on the PC didn't believe it could be done, I know Alien Breed and Gloom kind of proved them wrong, but the Name alone would of added a lot to the Amiga image.