plus gigai will be near impossible to replicate unless some caracters have identicle twins.
Not particularly. That can easily be done with computer animation. There are many movies lately that have such effects.
Anyhow, I think a Bleach live-action movie might be interesting... But I'm not holding my breath on it. The last few live-action anime adaptions have been pretty darn crappy (the latest DragonBall movie was a real nightmare), but if it's done well it could work.
'Course, I'm still looking forward to the Metal Gear Solid movie. And the live-action Robotech movie. Though I haven't heard much about either of them lately...