Been trying a little more to get MacOS 8.1 to work.
@Seiya
I do not have a copy of Oxyron Patcher, but i did try Cyber Patcher. However, the Amiga still reboots upon loading the MacOS Finder.
@stefcep2
Putting "cpu060 NOSUPERSCALAR" at the beginning of startup-sequence didn't help.
Regarding "rose" do you mean "A/ROSE" as in
http://en.wikipedia.org/wiki/A/ROSE ? I couldn't find any files with "rose" nor "prep" in the installation. I tried installing MacOS 8.1 again using custom install to see if I could see any reference to "rose", but I didn't. It may be labeled as something else?
I did try to boot with holding down SHIFT to stop extensions loading without it making a difference.
@Opus
Yes, MacOS 7.6.1 works just fine, so ill probably leave it there for now.