FO3 & NV had good amounts of blood; not necessarily realistic, but enough gore to satisfy.
They also had location damage.

Why did they not import this from their other games? IDK;
but maybe someone can mod it in.

If I had a dollar for every mod this game needs; it would have already payed for my copy.

You can decapitate a person, so I really, seriously, honestly doubt more blood would change the age requirement.

I want to see some guts pouring out.

http://en.wikipedia.org/wiki/Manhunt_(video_game).