I. Zax and Aeris were paired in game.
II. The time Cloud knew Aeris, he was part Cloud, part Zax. Therefore, it is possible that the part of him that was supposedly attracted to Aeris could have been Zack. Remember, he finds himself during disc 2, after Aeris dies.
III. I think this will about finish it. If you don't want to read it in full, just note the bold underlined words.
Game Script
CLOUD
"What are you going to do, Tifa?"
(She turns to him)
TIFA
"Did you forget?"
"I'm... all alone. I don't have anywhere to go."
(The scene fades out, then in to show Cloud and Tifa on a grassy hill. Tifa stands close to the camera, looking past the player. Cloud is behind her, staring in another direction. The Highwind hovers above. The only sound is that of the wind.)
TIFA
"Everyone's gone..."
CLOUD
"Yeah, we don't have anywhere or anyone to go home to."
(She looks down.)
TIFA
"You're right..."
(A pause. She looks up and straightens her hair with one hand.)
TIFA
"But... I'm sure someday... they'll come back, don't you think?"
(He crosses his arms)
CLOUD
"Hmm... I wonder...?"
"Everyone has an irreplaceable something they're holding on to..."
"But this time, our opponent..."
(A long pause. The sound of the wind fades. Tifa nods)
TIFA
"Hmm... But that's all right, even if no one comes back."
"As long as I'm with you... As long as you're by my side... I won't give up even if I'm scared."
(He uncrosses his arms and looks at Tifa.)
CLOUD
"...... Tifa......"
(She moves her arms behind her.)
TIFA
"No matter how close we are... We were far apart... before this."
"But when we were in the Lifestream surrounded by all those screams of anguish, I thought I heard your voice..."
(She closes her eyes, crying softly. Her arms fall to her sides and she bows her head.)
TIFA
"...sniff... you probably don't remember this..."
"But deep in my heart I heard you calling my name... Or at least I thought I did..."
(Cloud looks away and puts a hand to his face)
CLOUD
"Yeah... At that time I heard you calling me."
"You were calling me back in from the stream of consciousness in the Lifestream."
(He lowers his hand. He nods)
CLOUD
"After all, I promised. That if anything were to ever happen to you, I would come to help."
(Tifa opens her eyes and looks up.)
TIFA
"Cloud...? Do you think the stars can hear us?"
(She gazes off to one side)
TIFA
"Do you think they see how hard we're fighting for them?"
(Cloud looks up at the sky.)
CLOUD
"I dunno... But..."
"Whether they are or not, we still have to do what we can. And believe in ourselves..."
"Someday we'll find the answer. Right, Tifa?"
"That's what I learned from you when I was in the Lifestream."
(She nods)
TIFA
"Yeah...... that's right..."
(Cloud stares off into the distance. He turns away from her slightly and lowers his head.)
CLOUD
"Hey, Tifa...... I...... There are a lot of things I wanted to talk to you about."
(He shakes his head slowly.)
CLOUD
"But now that we're together like this, I don't know what I really wanted to say..."
"I guess nothing's changed at all... Kind of makes you want to laugh..."
(Tifa shakes her head)
TIFA
"Cloud... Words aren't the only thing that tell people what you're thinking..."
(Cloud looks at her. She continues to stare past the player, into space. She straightens her hair again with one hand.)
CLOUD
"............"
(She closes her eyes. The camera pans up, past her, to the sky, as the scene fades to black.)
************NEXT SCENE************
(The scene fades in once more to the grassy hill. It is still mostly dark out, but the hint of a sun is glowing beyond the horizon. Cloud and Tifa are seated on a small rise in the ground. Tifa is resting her head on his shoulder; both are dozing. Cloud lifts his head slightly.)
CLOUD
"............It's almost dawn..."
TIFA
"H, huh...?"
(He lifts his head further, just enough so that he can look at her.)
CLOUD
"Sorry. Did I wake you...? It's almost dawn, Tifa."
(She lifts her head off his shoulder and looks around sleepily.)
TIFA
"Umm... G, good morning... Cloud."
"Give me a little longer... Just a little bit longer..."
(She rests his head on his shoulder again.)
TIFA
"This day will never come again... So let me have this moment..."
(He nods)
CLOUD
"Yeah... okay."
(He lowers his head again.)
CLOUD
"This is probably the last time we'll have together......"
(The scene fades to black.)
************NEXT SCENE************
(The scene fades in to show the Highwind hovering in the bright morning sky. The camera pans back down to the hill. Cloud is still sitting down; Tifa has risen and is gazing up at the Highwind, her hands behind her back. After a few moments, she drops her hands and shakes her head.)
TIFA
"............"
(Cloud stands.)
CLOUD
"We'd better go."
(She turns to him and makes a pleading gesture.)
TIFA
"But, I still...!?"
(He turns to face her, shaking his head.)
CLOUD
"It's all right, Tifa. You said so yourself yesterday."
"At least we don't have to go on alone."
(A pause. Tifa nods)
TIFA
"Yes... That's right!"
(He nods)
CLOUD
"Okay! Let's go!"
(They walk together toward the Highwind. It begins to lower to the ground as the scene fades. It fades back in to show the walkway to the bridge. Tifa is following Cloud there.)
TIFA
"The airship is too big for just the two of us."
"Yeah, it's a little lonely without everyone."
(Cloud turns around to face her.)
CLOUD
"Don't worry. It'll be okay."
(He does his squat-thrusts.)
CLOUD
"I'll make a big enough ruckus for everyone."
(He stops and straightens his hair.)
CLOUD
"Besides, I'm the pilot."
"No more flying around casually like before."
"We won't have time to feel lonely."
(She nods. A long pause. Suddenly, the entire Highwind shakes as the engines fire up.)
TIFA
"Huh!?"
(She looks around.)
CLOUD
"It's moving......"
(They dash to the bridge. They find Cait Sith dozing in one corner. They run past him and find Barret and Cid working with the pilot's controls.)
CLOUD
"Barret! Cid!"
(Barret turns and looks at Cloud, then at Tifa, then back to Cloud)
BARRET
"O, oh...... is that okay with you?"
(Red XIII runs up to them from offscreen.)
CLOUD
"Red XIII!"
(Cloud and Tifa look back to Barret.)
TIFA
"Why didn't you tell me!?"
(Red XIII looks at Cid, who still is operating the controls.)
RED XIII
"But, you know, Cid."
(He looks at Cloud. Cid leaves the controls and stares at Red XIII.)
CID
"Hey, Red XIII."
"If you butt in now, you never know what they'll say later......"
TIFA
"......Were you watching?"
(They watch her as she runs away, clutches her head and falls to the floor in embarrassment. Vincent enters the bridge. All except Tifa turn to see him enter.)
I think that implies. Now, don't get all rabid on me, I just want to put forward and back up my opinions.