ihaveherps, there have been hundreds of articles written on the topics you mentioned in the last 10 years that provide answers to your particular questions. A good starting point is the work of Richard Wrangham, a controversial Harvard anthropologist who attributes human brain development and many other physical developments in humans to the consumption of cooked root veges rather than red meat.
Also, it's interesting to note that human brain size has actually decresed by 11% in the past 35 000 years, whilst the consumption of red meat has increased.
There is a LOT of evidence to suggest that the reason the caecum and appendix is a lot smaller in humans that it is in other herbivores is due to a combination of the fact that humans historically consumed a diet high in nuts and seeds, many of which do not contain digestable cellulose, and the fact that cellulose walls are softened when heated (cooked). You can also check out the comparative sizes of the appendix in humans as opposed to our closest relatives, monkeys and apes - the proportions are similar in these herbivores to our proportions, and some species do not even have an appendix.
(And for those of you who will argue that apes are in fact omnivores as they consume red meat on rare occasions, mostly in a canibalistic nature: do a little more digging and you will discover that after eating red meat, they will ingest toxic herbs to purge the meat before it is digested).
For more info and heaps of articles, just navigate to
www.google.com and have a look-see, that is if you actually care to read the opinions of various academics that are contrary to your own... if you're just here for a flame session, as i suspect you are, and if you're completely uninterested in taking anyone else's theories on board, don't bother adding fuel to the fire. I realise that the widely accepted opinion in this day and age is not my own, and it's conversations like these that have led me to read up on the issue a lot more than your average meat eater, as I switched to a vegan diet for health reasons rather than theoretical ones. As most people have learned to accept this common belief from a young age they're, more often than not, opposed to changing their stance at a much later date. If that were the case here, as it is with most people, there'd be no point in me referring you to books or articles, and the only thing I could further suggest would be that you try a vegan diet for 3 months and see how much better you feel. But I really can't see that happening either.
For this reason, I'm not going to continue with this discussion on this forum and besides, it's waaaay off topic, if anyone wants to continue chatting about this stuff, PM me.