@Kin-Hell
I don't have a classic OS4 setup so I can't help too much, but I do have OS4 on an A-one.
Let's see if I have this right: you installed OS4 ok, but have networking troubles causing lockups, after which OS4 won't startup properly. Is this about right?
I'd suggest trying the following:
In s:startup-sequence, change this line:
C:AddNetInterface QUIET DEVS:NetInterfaces/~(#?.info)
to
Run >NIL: C:AddNetInterface QUIET DEVS:NetInterfaces/~(#?.info)
The original line will wait until your ethernet card is connected, has an IP address, etc. If you're ethernet driver is not working properly, this can cause it to stop at this point. Adding run means that the startup will continue, even if you can't get connected (unless the machine really freezes).
I'm guessing, that the driver and your ethernet card aren't working together properly. Not being able to startup after IBrowse locks up suggests that the ethernet card ends up in some unknown state and doesn't get reset properly. This would cause addnetinterfaces to just sit there.
BTW, what ethernet card are you using? Your sig only mentions 10/100 ethernet. Hopefully you're not the only one with that card.
I know that this is frustrating, but, with the number of different cards in use on classic Amigas, supporting all of them is a huge undertaking. They're planning to release an update that fixes at least the graphics issues and Mediator LT (or whatever sub-model) problems later this month.
Hans