I'd probably go back to the A1000 release year, so that I could get an Amiga early on! Whilst still enjoying the prime of the 8-bit years. Anything after 1992 was just rather depressing in Amiga-terms!
I'd go back to '86 and buy commodore and kick out all the mgmt wankers that ruined the company and make sure the Amiga was the only focus for the company (no c64/65/128 distractions - still sell c64 but that is it!)!
I'd make sure CD-Rom support for a1000/a500/a1200 was implemented far earlier than it was - FFS why couldnt they see CD + Amiga = WIN!!!
I'd have also given AAA much higher priority much earlier on on not wasted all those years after the a1000 finding new ways to package the same HW that was basically released in '85!
Isnt hind sight a wonderful thing? :whack: