Rumors and Secrets
This will allow you to know some of the secrets to the game as well as rumors.

Final Fantasy VII and Final Fantasy Tactics
There is an opportunity to gain Cloud as a character by transporting him from the past in Tactics. Before he actually joins your party, he'll disappear, later reappearing after fighting some enemies. And guess what? Apparently Cloud had been defending a 'flower girl', Aeris?

Hidden Items
Apparently using a gameshark or computer application one can acquire two letters. One letter is to a daughter in Kalm, and the other another letter to a wife in Kalm. The letters have no effect on the game and could have represented a mini-quest that was later delted from the actual game.

It is possible the 'Letter to a Daughter in Kalm' may be related to Marlene. She is the (adopted) daughter of Barret and resides in Kalm. However, this is questionable. If the letter was intended for Marlene, the letter should have read 'Letter for Marlene'. Instead, the letter suggests the daughter is unknown to the party, and perhaps must be hunted down.

That leaves the 'Letter to a Wife in Kalm'. Likewise it suggests the receiver is unknown to the party. If the receiver was indeed known, the only possible person can be Elmyra, Aeris' guardian. Following events in Midgar, both she and Marlene relocate to Kalm. Over a decage ago, Elmyra's husband served in the Shinra military and was killed during the war with Wutai. Perhaps this letter was from her long-dead husband before he was killed? And the letter to Marlene may be from Dyne, her real father who tragically kills himself when rediscovered by Barret in the Corel Prison.

The Ancients

Ancient Cave
A mysterious cave exists on the path towards the Ancient Capital. It is partly hidden by the shadows of a cliff.Notice the vine and pathway leading to the cave. You'd think there would be a way to enter the cave, there isnt. More then likely this went to either a secret item or a mini quest later abandoned.

Vincents Age
The manual states the age of Vincent Valentine as 27. However, remember how Vincent had previously worked for the Turks before Sephiroth was born?

  We can safely assume Sephiroth must be at least 21 years old. If Sephiroth was born twenty one years ago... then Vincent must have been six years old during that time, and hence way too young to be a Turk. So, how is this possible?

The human mother of Sephiroth was a scientist named Lucrecia - Vincent's love. She was seduced by Professor Hojo and impregnated with Sephiroth. Vincent vehemently opposed this plan, but was sadly 'disposed' of by Professor Hojo. The professor 'scientificically altered' the ex-Turk and 'put him to sleep'. It is possible this form of 'sleep' is a form of suspended animation. As Vincent 'slept' in his coffin, the years would pass by until that fateful day Cloud intruded into the Shinra Mansion. When Vincent at last re-emerged from his coffin, he was still the same age as when he was first entered. (If you do not understand this you can easily relate it to those who are cronology frozen to prevent their bodies and organs from aging.)