I was looking through finalfantasy.wikia.com to see what exactly made FFII SNES and FFIV otherwise so different that FFII would be considered "easier". As far as I can tell the only thing that makes FFII a little bit easier is the open availability of Remedy's and Ethers, when you have the money to splurge on Ethers. None of the enemy stats are changed and I would argue that some of the battle items (curtains, bacchus wine, Spider Silk) actually ends up making things a bit easier.
While in this I saw a version of FFIV that I'd never even heard of before...
"Mobile PhoneEdit
The following is from the mobile phone port of the game, which was only released in Japan so far.
All new character sprites for during and outside of battle, with some taken from Final Fantasy IV: The After Years.
The party-swapping feature from the Advance edition is reinstated, with some rebalancing on the characters.
A whole new "EX Dungeon", which is a heavily redesigned version of the Lunar Ruins and shares the same entrance. The stories for the Lunar Ruins were changed.
The inventory space is now unlimited. The Fat Chocobo is now used for a minigame. If the player finds one of eight Gysahl Greens from around the world, they will receive a reward from the Fat Chocobo in the Chocobo Forest.
Namingway has been replaced by Tradingway, who must be visited in seven different locations. Each time the player meets him, they will get a Colored Card and an item. Collecting them all will award the player with the Unhappy Ear Hood, which refers to Namingway's ears.
Other than the Pink Tail, the player can discover other tails in exchange for items. These include items that were seen in the The After Years, such as the Rapid Ring and Rare Band."
Now this actually sounds like an interesting little update and would have been neat as an add on or DLC or something for the Complete Collection. What interests me the most is that apparently the Lunar Trials stories were changed. I love FFIV to death and every iteration of its world and characters always fascinates me, so I would love to know more about this version if possible. I am also curious to know what rebalancing efforts were done for the end game.