Chiaki J. Konaka was the story developer of Digimon Tamers and wrote screenplays for at least 15 episodes. Not long ago he uploaded those screenplays on his website and I decided to look at the ones that have Rika and Ryo scenes in them to see, if there are any major differences between the original script and the final cut of the episodes.
As you will see below the script and the final episode are very similar - the conversation between Rika and Ryo is more or less the same, there's some of it missing or added in the final episodes. The biggest difference is probably the much bigger emphasis on Sakuyamon's buddhist spirituality that I didn't really notice in the show itself (because, well, I'm not familiar with Buddhism very much). In the screenplay Justimon actually uses buddhist terms (like Vajradhatu Mandala) when asking Sakuyamon for her power (and Mandala) and Konaka, too, uses them when describing Sakuyamon's actions (like the staff she's holding actually has a proper name). It's really interesting but more about it somewhere else.
The screenplay is obviously more rough than the anime and it contains the most important parts of the plot. We get some extra information on the emotions the characters are going through but a lot of non-verbal details are then added in the final episodes. This is where I noticed most of the differences in Ryuki scenes but like I said, the essentials are in the screenplay as well.
So let's see my translations of Ryuki scenes in episodes 41, 50 and 51 of Konaka's screenplay. I put my comments in brackets // like this //.
EPISODE 41, The Return to the Real World!
(The ark starts moving but Ruki and Kyuubimon aren't back yet. Terriermon is sitting on Jian's head and asks him if he should go and check for Ruki and Renamon but Jian throws him inside the ark saying he needs to board it.)
Cyberdramon spreads his wings, puts Ryo on his shoulder and they fly away.
JIAN:
Thank you!
// Ryo comes off less of a hero-boy in this scene because it's obvious Jian thinks it's better to wait and Ryo doesn't just jump in to be the hero. //
(Guilmon manages to stop the ark from leaving and Jian hears Ryo's "Heey!" in the distance. Kyuubimon with Ruki on the dusty ground and Cyberdramon with Ryo in the air are rushing towards the ark. They successfully board it, Kyuubimon digivolves back to Renamon and Cyberdramon back to his Rookie level.)
TAKATO:
Well it's great... you made it in time.
RUKI (smiles awkwardly):
I'm sorry...
// I really like this moment both here and in the final episode when Ruki feels bad for what she put them through and apologizes. //
RYO:
Thanks to you guys I too can go home for the first time in about a year.
RUKI:
You're such a bad kid.
RYO (grins):
Back at you.
// Ryo's comment was actually meant for Ruki, even though he doesn't specifically adress her other than looking at her; Ruki's non-verbal response and Jian's smile are added later. //
EPISODE 50, Crimson knight! Save the people you love
(Jian, Takato and Ruki meet at the Digital glide (the bubble) where Jian introduces the Red card that will help them stay in their Mega level inside the D-Reaper bubble. A sudden loud woosh interfers.)
JUSTIMON'S VOICE:
I hope you haven't forgotten about us!
Digital glide opens up and Justimon jumps inside - evolving back to Ryo and Cyberdramon.
RYO (raises a hand and says refreshingly):
Yo!
TAKATO:
Ryo-san!
RUKI:
It's not like we forgot about you, though.
// The two scenes in episode 50 are completely the same in the screenplay and the final cut; I do like how Ryo's refreshing Yo! is emphasized here. :D //
RUKI (just a bit anxiously): This is a real fight now, right... not a game.
(her face gets a strong looking expression) And I'm the girl who was called the Digimon Queen!
SAKUYAMON:
But Ruki...
RYO (chuckles):
Maybe you really are the Queen. But in that case I'm the King.
RUKI:
Oh shut up!
TAKATO (lets out a quiet laugh):
We really haven't changed...
EPISODE 51, The Power to Dream is Our Future; The Biggest Dreamer
Justimon suddenly changes his arm into a cutter. // Justimon's arm is first called the cutter (edge) and it later turns into a shining blade. //
SAKUYAMON:
What is this nonsence! If I do that...
◯RUKI & RYO*
RUKI:
What do you think will happen to your body?!
RYO (grins):
Only Vajradhatu Mandala can spread! If you charge all that power into Justimon's cutter we'll cut it in half!**
RUKI:
Exactly! Like I said, it's too dangerous for you!
RYO:
It's the only thing left for us to do. Please, Ruki.
JUSTIMON:
I'm not that weak to get killed by it!
RUKI:
Ryo... Looks like you are the most reckless one of us after all.
RYO:
Thank you.
RUKI trying hard to hold back her tears, biting her lips.
SAKUYAMON:
Are you sure? Ruki...
RUKI:
We're here to win! I believe in Ryo and Justimon!
* = the two scenes are actually interrupted with the sign (◯RUKI & RYO) where the circle stands for the space/whereabouts of the scene that follows; here Konaka emphasized the meaning of this scene by giving it its own space - surrounded by ◯Inferno on both sides since the scene as a whole is happening inside the D-Reaper (inferno) bubble (see the picture below)
** = I have no idea how to better translate this Mandala sentence ~~
// The scene is just a bit different than in the original cut (Justimon saying he won't get killed by the transfer and Ryo saying thank you to Ruki without commenting how this was the first time she'd praised him) but my two favourite parts of it are there: their "inside joke" about who's the more reckless one & Ruki tearing up (and even biting her lips) when she decides to trust Ryo ♡ //
(Sakuyamon does the power transfer through a purple power field. Justimon and Ryo scream in agony while receiving it. Saint Galgomon watches them terrified // this is actually mentioned // and Sakuyamon and Ruki have no more strentgh left. Justimon's cutter hand becomes a shiny blade (JUSTIMON: We really got Sakuyamon's power!!!). And then just like in the final episode he fails to defeat the Reaper and it's the four Sovereigns who come and drag it into the abyss.)
Screenwriter for episodes 28, 29, 39 and 46 was Genki Yoshimura, who - according to Konaka's website - was in charge of Ryo's character development since she was the screenwriter for the first episode he appears in. It seems to me she was quite fond of the relationship between him and Rika. :D