Well, how many people do you know have gone through an involuntary sex
reassignment?  :)  This is all hypothetical, of course, since this just
won't ever happen in the real world.  Ranma's change just isn't
physical, it's biochemical, right down to the ability to give birth. 
It's something we can't even begin to imagine.

        A la Nullifier style.

I sort of wrote it from my perspective, too.  I am heterosexual, very
much so.  Although I have no problems with someone choosing
homosexuality as a lifestyle, personally it's something I could never do
myself.  However, if I was put in Ranma's situation, I *could* imagine
myself making the adjustments he did.  Maybe I'm a weird hentai.  :)

You're not alone in this paragraph.  Would Ranma rather pine away, as a
girl, caught between two warring feelings of sexuality?  She can't love
girls, probably has a problem with loving a lesb, but she can't love guys
(yet), but has no problem, biochemistrically, loving a guy.  Gut instincts
can't be supressed when they appear - and Ranma IS a girl, not RuPaul or
some other crossdresser.

Akane would *not* be able to marry a woman.  Your points above, about
changing sexual preferences, apply to Akane.  She just wouldn't be able
to do it, I think, and their relationship would change.

A la Nullifier style, again.

And you forgot the last option that Ranma could have - have a sex change
operation.

Sure.  When Principal Kuno and Akane get together, that is.  I don't think
she'd settle for anything less than her original male body, not some
haphazard graft of unnameable body parts on her female body.  

This wouldn't work.  Such changes are only skin deep; he'd still have
two X chromosones underneath.  He'd know the difference between a true
man's body and a woman's body altered to be a man, and the differences
would drive him crazy, IMHO.  It would be a pale imitation at best, and
I think Ranma is intelligent enough to know that.

Nod.

ATTENTION FFML'ers:  If you suddenly found yourself turned into the
opposite sex, down to the level of your chromosones, and such a change
was IRREVERSIBLE, would you:

B)  Keep your body and CHANGE your sexual preference;

        I'd go for this.  Far better than not experiencing love.  In the
end, in one's declining years, love, not the body, is what counts.