Ok ok, so the - in Ran-ko is tedious, sue me, im the one writing here! ;)
That song u were talking about i think is called 'Ritoru Deito' (Little
Date) 2nd season opening right?

I don't believe that Shampoo scares Ranma one bit, he's been reluctant from
the start to let her kiss him namely coz if he's seen then something large
and mallet-like in shape and proportion will be applied to his head ;) He
even admits it in the manga when he is thinking about Shampoo after getting
whacked by Genma for being a wimp in standing up to Shampoo's claims (Book 3
in Viz's translations i think) He admits that Shampoo is pretty cute.

As for Ranma getting annoyed with Shampoo crashing into him, wouldn't you
get annoyed if it happened to you day-in, day-out? ;) Ranma wouldn't think
of Shampoo as a future wife, no, i doubt he has the guts to. But in his
current state of thinking that Akane does hate him, he may be looking for
something to take his mind off his troubles and i think we all know what
Shampoo is like, Nuff said. Though i could have Cologne guess what would
happen and pump something into the room. (NO Cologne is NOT going to take
part in any lemon. if i DO put her in, i implore the world to stab me to
death with blunt objects then hurt me! *grin*)

Ran-ko's character isn't that much of a problem, think of her as someone
who's been 'reborn' after 1500 years into a strange new world. She'd be
quiet and tentative at the start, not willing to get into any arguments etc.
She doesn't 'know' what Ranma knows as she doesnt have his memories, when
the split occured, it did just that, she may have some knowledge but it'd be
hard to remember when your mind just got swapped. 

Ok, look at it this way, the spirit of the girl in Ranma's body, when she
was still in his body, she knew what he knew etc, when the split happened,
anything that was her, memories, her past life before death etc was all
taken and transferred to Ran-ko's body, leaving Ranma as he was before he
fell in the pool. Basically, he's cured. Ran-ko MAY still remember some of
his thoughts from being in his body but when your mind gets ripped from one
that you've shared with for so long, it would have something to the effect
of a mindwipe.

Hope that clears it up a bit about Ran-ko. I would appreciate ideas on how
to to the lemon tho. Ranma awakens in bed and finds Shampoo bending over a
table sorting thru a pile of medical herbs etc etc, go from there ;)
      K  u  s  a  n  a  g  i       K y o
      --|---|--    --|---|--     ----+----
       +-----+     /-, +-+-       +-----+
       |-----|      |  |-|-       |     |      
       +-----+     -|- |-|-       +-----+
      ----|----    / \ +-+-       /  J  \
 -----------------------------------------------
  "Kusanagi Flames, Yagami Tears, Orochi Blood"