beginner type questions

[Durant, Dean]

Hello, I noticed, on windows (which I truly despise), when I type 
 
C:\Documents and Settings\me\Application Data\gnupg>gpg --gen-key
 
I get:

gpg (GnuPG) 2.0.12; Copyright (C) 2009 Free Software Foundation, Inc. (add'l copyleft info)

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
 
on ubuntu, I get these choices (the version of GPG is 2.0.9):
Please select what kind of key you want:

(1) DSA and Elgamal (default)
(2) DSA (sign only)
(5) RSA (sign only)

What is the difference?   Isn't RSA better?

I tried using apt-get to get the version on linux up to the same version # on windows, and it wouldn't.  

Once you generate a key, is it bound to the email address supplied during generation, so that, if someone else emails your key out, you won't be able to decrypt something encrypted to their email?   Or is the email address completely uninvolved?

Thanks, Dean