I was wondering if its possible to increase the explosive radius of a Fusion Coil or any explosive if I went into Forge and messed around with its properties with its shape and radius. Can anyone tell me if I could do that or not?
Definitely not possible. Could you explain what you're trying to accomplish? That'd make it possible to find an alternative.
If only you could activate skulls in Multiplayer, then yes, you could. I think it's the cowbell skull.
One will detonate and cause the other two fly in a random direction then detonate a moment later. This is much more unpredictable, functions very differently than just a larger explosion, and can cause serious lag if more than two fusion coils are involved.