Trinisphere: Its interaction w/ pitch spells and activations

[Jhaggs]

I'm not sure I have trinisphere thought out correctly so please set me straight if I am totally on the wrong track.

1.  If my opponent has trinisphere out in play my force of will's will now cost me 3 mana to play.

2.  If my opponent has trinisphere out in play and I have fire/ice imprinted in isochron scpeter, my fire/ice spells now cost 5.  This is due to the 2 mana for the activation cost and the 3 mana because the actual spell has a CC of 0.

3.  If my opponent has trinisphere in play, all spells off my resolved mind's desire costs 3.

My logic is as following:  Trinisphere affects the total casting cost of spells.  Even if those spells have an alternative means to playing them you still have to look at the total casting cast cost.  FOW, iso, and mind's desire have total casting costs of zero.  Since trinisphere is in play you must add 3 mana to all zero cc spells.

Do I have this right?

[Jebus]

You are completely correct on all points.

[Jhaggs]

Thanks Jebus.  Making FOW 3 mana to play makes trinisphere even more dangerous.  This card clearly has potential.