Ressha Sentai ToQger's connection to Final Fantasy

FF1:

Red is named Light, a Light Warrior? He's a Red Fighter as mentioned in one of the subs.

FF6:

The most obvious: the Phantom Train

FF7+:

Effeminate Male Protagonist with dyed hair.

Where the train goes philosophy.

Sephiroth, the Tree of Life, and the Ancient Forest.
Childhood friends Cloud and Tifa, Mio and Tokatti

FF8:

Forgotten memories like Ryuki and Boukenger, especially regarding childhood.
Doomtrain