.emacs and other config file questions

[Tommy Kelly <tommy.kelly@verilab.com>]

Back to using emacs after a long absence. This is partly a test to see
if I've set up Gnus properly so as to post to gmane. But I've a few
acatual (although probably old and well-worn) questions on emacs
configuration. I've browsed gmane archives and googled about for info
but can't find anything definitive: 

1. "customize" versus Do It Yourself?
=====================================
Is there a general view as to the pros and cons of using customize
versus just writing the lisp yourself? Although I know very little lisp,
I'm inclined towards the latter -- primarily so I'm forced to
learn. Customize is cool and easy and simple, but I worry it leaves me
dependent on it. Make sense, or am I just trying to punch nails in with
my fist when even the cool kids these days use the customize nailgun?
Found a few items on this, including
http://article.gmane.org/gmane.emacs.help/25218 which references
something back in 1999 that I couldn't locate.

2. Why .gnus (and no, for example, .org)?
========================================
Gnus seems unusual among the many packages in that convention seems
to dictate we do most of its setup in .gnus, rather than in
.emacs. Why is that? After all, there's no similar "special" file
expected for, for example, org-mode or Newsticker or Rcirc. Is there a
problem with ditching .gnus and just putting gnus setup stuff into
.emacs (or something loaded from .emacs)? This is connected with the
earlier question about customize. If I use customize then I can find my
gnus setup info gets split into two places: my own code in .gnus, and
customize's stuff in (by default) .emacs. That's a bit smelly, no? Or is
there some stuff that *must* go in .gnus because it makes no sense until
Gnus is actually run? 

Finally, something touching more than emacs, but in my case specific to it:

3. Mirroring the above?
=======================
I'm running primarily on a desktop iMac, but would like to run also from
a MacBook Pro Laptop. I have DropBox. I also have iDisk (MobileMe). And
in the past I've used unison. Anyone care to share how they handle their
config setup (i.e. their use of .emacs, customization, .gnus, and so on)
where they want the same setup mirrored across multiple machines?

thanks,
Tommy