There are so many contradictions now that I believe that it could either way, and neither view is wrong. I believe Aerith loves Zack. And just to point out the contradictions, there is a quote for every one that you posted that says the opposite. xD Observe:
Cloud is the woman’s friend, beloved/lover/sweetheart (koibito)—-he is a symbol for something important, an existence that she must protect. - Case of Lifestream: White
"The destined encounter with Zack makes them becomes the irreplaceable existence to each other."
"The more Aerith knows about Zack, the more she’s attracted by him. Her manner toward Zack is also sweet."
"Repeating Zack’s look with Cloud’s.
Being an Ancient, Aerith did her utmost to save the Planet, even sacrificed life—in FF7, the impression of Aerith being such a tragic heroine is strong. Nevertheless, the most significant link to FF7 is the conversations about Cloud. The reason why she’s a flower girl when she first meets Cloud, the beginning of love with her first love, Zack, and the reason she saw Zack in Cloud—all those things we don’t know in FF7 are made clear in CC.
Text: Aerith asks Cloud to be her bodyguard. Does her “one date” as the payment repeat what Zack used to say to her?"
"*Text near the img of Zack and Aerith in CC:
Aerith never talks about her bitterness but lives brightly. It is growing by degrees into inseparable relationship."
"Nojima: The setting that “falling from the roof of the Church” repeats Aerith’s encounter with Cloud was decided in the beginning. Though we’re talking about love, they are still young back then and there’s no time to describe “how they become fond of each other” in the game. So I made it like “falling into a sudden crush.”"
( The other two quotes of yours are true, arguably not romantic )
AERITH: “I was a little surprised that this village was Zack’s birthplace! Although called my first love, that doesn’t mean that we became particularly intimate. At first when I met Cloud, I believed he was similar to Zack. Little actions, the way he spoke… his kindness. But Cloud is Cloud. I, now undoubtedly, love Cloud much more than Zack. But Cloud is clueless.” - DISMANTLED
"The dull life in the Slum, the love with a SOLDIER who fell from the sky."
"She met Zack in the Sector 5 church, and became very
intimate with him."
"Aerith, the girl whom he met at the slum's church. The existence of the girl, who had earnestly come to love Zack with sincerity, eventually became irreplaceable to him."