however the sci-fi channel is greedy, so threatening to cancel stargate sci-fi forced brad wright to get rid of one of thier original cast and put some of sci-fi channel's add-in cast,
Ah, what? The only cast change when SG-1 moved from Showtime to SyFy was Michael Shanks leaving and replaced by Corrin Nemec. Shanks wanted to leave on his own accord, and Nemec was cast before the show officially moved to SyFy anyway.
on top of that sci-fi wanted full rights to the show after he agreed to it, sci-fi threatened to cancel the contract and sue for rights to SG-1, so brad wright pulls the show and cancels both SG-1 and atlantis, Sci-fi then claims stargate and releases universe that didn't even last a full season.
1) Atlantis was cancelled two years after SG-1 was, and both were cancelled by SyFy.
2) SGU in fact ran two full seasons.
3) Brad Wright was as involved with SGU as he was with SG-1 and Atlantis.