Himalaya- Just to reiterate, though nothing I am saying is contrary to Catholic teaching, the church has not really made any pronouncements on life before the fall, so these are my personal thoughts.
We can look at the universe we have now all we want, but because it is, in effect, corrupted data we can't extrapolate to precisely what it would have looked like before the fall.
When I say there was no entropy before the fall, I mean it in it's form that we see now- an inevitable, inexorable path to universal heat death. That does not prevent God from creating things by slow means of evolution, or instantly bringing them into being. There would be no difference in the final result we see now.
Adam was the first Man, period. If it has no soul, you cannot call it a Man. Were there bipedal mammals walking around? Almost certainly, but they weren't creating wall paintings or little Venus carvings.
I believe God created the world for Man. I believe that had the fall not occured, we would have had a universe that would effectively go on forever, sustained by God. After the creation of Eve, Man would begin procreating, populating first the Earth, then the planets, then the whole universe.
I believe that before the fall, there was no time as such. I believe things happened one after another, but I don't think it was binding like it is now. Frankly, (and here's where I go totally off the wall) I think Eden was a bit of a TARDIS, a nexus from which mankind would have been able to explore every corner of God's creation. Thus, when Adam ate the fruit of the tree, the effects were disbursed through every point and time as we know it came crashing down, locking everything into a one way street. That was the point where we were kicked out of Eden and had to make do with what we found.
And no, I've never taken psychotropic drugs in my life, thank you very much 