Valkrionn
The Hamster King
And that alone should make you wonder if it really is a possitive addition to the game. It's not a simple case here, normally you'll look at a feature and see it it adds something to the game when considering it, in this case you have to consider what it's taking away from the game. Moving your units around is but a small part of playing a game of Civ and that is all that every player except one can do when this is active.
If somebody was to suggest a new feature for the game that would remove roughly 2/3rds of what everybody else could do, what would your first reaction be?
Actually, that tells me that it is a positive feature. World spells should be things that are hated by other civs, abilities which can change the course of the game if used correctly. Stasis does that perfectly.
And honestly, I'd far rather be on the receiving end of Stasis than one like World Break or the Lanun spell. Better to be unable to build new units than to lose your experienced ones, or worse, your buildings.
That's irrelevant really. There are plenty that are bad for different reasons and many that are decidedly worse than others but none that are as bad for general gameplay as Stasis.
The problem with Stasis has nothing to do with it's 'power' be it real or perceived, it has everything to do with taking away the ability for the player(s) to play the game. A world spell that you have to react to by doing something extra is a good addition to gameplay, a world spell that you reaction to is simply doing less is not. It is still a game after all, it's supposed to be something you enjoy, not something you endure
You can certainly leave it as is, I'll do what I have been ever since FfH added Stasis, I'll go into the xml and set the Illians as a non-playable civ. Since I'm obviously not alone in my dislike of the mechanics of Stasis you should keep in mind that any work you do in RiFE that is directly or indirectly dependant on the Illians is wasted on a number of players.
Again, I'd honestly say that the Lanun spell is worse for gameplay than that of the Illians; Instant loss of your army is far more of a hit.
And hell, don't even need to modify the xml. There's a game option which allows you to set playability.
Also, as I think I've said there will be a tech requirement for it; It IS too much for the earlygame.