Purely from an FFVII perspective? It almost sounds like you're trying to find a reason to ignore certain pieces of evidence, but I'll take you on, because it can be done.
I'm going to jump to farther on in the story to what I feel is most prominent. In the Lifestream we learn that many of the things that Cloud did, he did to impress Tifa. He wanted to be friends with Tifa, to be noticed by her. It's why he called her out to the well, it's why he went to join SOLDIER, it's why he always got into fights as a child. He wanted to be noticed, ans when Tifa doesn't get it and asks who it is he wanted to noticed him, he says, "Who? You know who! You that's who!"
And when Tifa says that she checked the newspapers for world of Cloud everyday, his younger self says, "You should tell him that, it'd make him really happy."
Why would Cloud fight so hard for Tifa's attention? Why would the current adult Cloud be happy to hear that Tifa had been so adamant for word of him while he was gone?
In the first visit to the Northern Crater Cloud tells Tifa that her opinion is the only one that mattered to him and that he would believe whatever she told him.
The math speaks for itself.
And Aerith hanging around him on the first disc? That's just Aerith being who she is. And wanting to find a new Zack in the process. You've said so yourself that was the case.
And your opinion is that Cloud loved Aerith and you think that's right and that's why we should believe you? I can go there, too. I think that Cloud loved Tifa and I think that's right so maybe you should believe me.