squall comes from ff8, cloud comes from ff7, tifa ff7, yuffies ff7, cid ff7, aerith ff7

It was a prequal to FF7, which means there is no 'next' unless they remake FF7 or create a sequal to FF7, which there is no news of at this time.

Why on earth would you want to? Aerith accomplished much more after death than she did while living. Everyone are where they belong.

Yes. The night under the Highwind Cloud attempts to confess his feelings to Tifa. But unable to find the words Tifa utters the infamous "Words aren't the only way to tell someone how you feel".

From Tifa's profile Crisis Core Ultimania:

"In FF7, Tifa is the only one who knows Cloud's childhood, and furthermore, she holds the key to people involved in the story of Nibelheim's burning down, which is also depicted in CC. She and Cloud came to realize their feelings for each other in the end of the story, and live together in AC and DC."

There are technically two version of this scene. But only this version is brought up in various character profiles and was called an important scene in the game by the creators. In the other version Cloud and Tifa don't communicate much at all.

No, 'Before Crisis' is a mobile phone game set 6 years before the events of the original Final Fantasy 7. It concerns the Turks, fighting against AVALANCHE.

'Crisis Core' is a PSP game, the events portrayed within are set a short time before the start of Final Fantasy 7, and mostly concern the backgrounds of Zack Fair and Cloud Strife.