I was just about to post that I'd sorted the problem
It is indeed that file.
Emulation in a window is acceptable, although not what I'd call blindingly fast. It's configured to use JIT with an 8MB cache. I strongly suspect that the EUAE Universal Binary that I'm using is hamstrung by an SDL framework that's PPC. I've not yet found an Intel SDL build to confirm this, though. I've not fully tested it, but apparently EUAE is faster full screen, which is about right for SDL anyway...
My Installation on OS X is a cheat, though. I have access to a windows machine at work, which I had Amiga Forever Installed on. All I've done is run the AmiKit installer on the windows box and pointed it at the AF installation and ROM files then let it do it's thing.
From there, I've rar'd the resulting AmiKit file, ftp'd it to my MacBook and then using HiToro, set the correct paths for the rom files and edited the HD path to point to the new AmiKit folder. The only change that needs to be made to a base AmiKit install is the removal of this DosDriver file. The standard startups all work straight out of the box.
I'm 100% confident that if you provide a base AmiKit zip or rar package that the rom files and AF installation files you copy during the windows installer can be scripted to be copied in much the same way under Linux or OS X. There's probably more work involved in getting Amiga Forever setup on OS X in the first place, so I'd suggest the easiest way is to do similar to me; setup on windows then move the result lock stock over to OS X.
The only glitches I'm having are:
LiveUpdate is reporting it's unable to connect to the server. Not sure if this is fact, or peculiar to my setup right now.
The screenmode is stuck on 800x600. Despite saving my preference to 1024x768, it pops open at the lower res, then if I'm lucky on a later attempt via screen mode, Intuition will pop it up to the higher res. This is a bit hit and miss though, as the start bar, calendar etc will restart before intuition's able to resize. Not a big deal and something I'll fiddle with later.
All in all, my cheaty approach was pretty much painless, so cracking work and thanks