Ok, finished investigation:

1) DNS issue: "Due to current limitations in busyboxs wget and DNS resolution, 
an URL can not contain a hostname but an IP only."

2) Regarding the 60 tries for setting up NFS: "This while loop is an ugly HACK 
round an nfs bug"

So both issues are limitations of existing software. I don't see anything we 
can do to solve those issues now, hopefully the situation will improve with 
implementation of live-initramfs 2.x.

I'm setting this bugreport to status "deferred" for now (so the issue is 
visible for some time), if anyone comes up with a solution to address this 
issue I'd be happy to integrate it both in Grml as well as upstream.

thanks && regards,
-mika-