As you note, there is some ambiguity in the Scriptural references
as to whether meat is proscribed, given that Abel sacrificed a lamb and
Noah knew which were clean animals (and unclean animals could be
domesticated, just not eaten or touched after death-horses and camels being
obvious examples). It's also possible that a special proscription was made
for Eden, and part of Adam and Eve's job in subduing the earth was to be
extending this.
Although there are difficulties in reconciling these, it seems
better than denying the evidence for predation before the end of the Flood.
The oldest known evidence for predation (holes in shells) is late
Precambrian. Many YEC's still claim there are no Precambrian animal
fossils and assign those beds to before the Flood. Gut contents or
coprolites (fossil fecal material) with animal remains extend back to the
Cambrian, and there are healed scars on shells (demonstrating attack on a
live animal) also in the early Paleozoic. All flood geology systems I know
of assign these to before the end of the Flood.
Parasites also occur as fossils in deposits of many ages. The
current trend in the ICR seems to be identifying the K/T boundary as the
end of the Flood, in which case there are biting flies and mosquitos in
Flood amber (incidentally, one of the few accurate details in Jurassic
Park). The existence of parasites is a problem also overlooked in YEC
special creation accounts that I've seen. If all "kinds" were specially
created before the fall, and a "kind" is roughly equivalent to a Linnaean
family (a view approvingly credited to Gish by Huse), then either many
parasites must have existed before the Fall or else the subsequent
"microevolution" [as defined by YEC's] created many complex systems such as
multihost life cycles and specialized defenses against the host.
David Campbell