Ok !!!It's almost perfect.
1- I can boot without boot flags now.
2- GFX acceleration is perfect now.
3- Creative cloud and Photoshop + lightroom installed and work Ok
Some remaining issues :When I start the computer my two monitors are working fine, but when OS X starts (on OSX startup there is the apple logo with progress bar on two monitors) the "logo page" shuts down and I arrive to the login page on only one monitor, I need to toggle on/off the second monitor to have the dual screen again.As I did some mistakes on the first install, I did it again today, it worked fine, but on the previous install I plugged in another HD (data storage HD), formatted it on OS system, and when I plugged it again on the new system I have permission problem. I managed to solve the permission on the folder system but the files remained on permission error. I managed the permission issue with the info dialog box and applied it to the included elements but it didn't solve the file permission issue. Only the folder permission issu. As I have 20000 images on the HD I can't do the operation on each single file ! Is there a way to change permission (in fact it seems to be a permission remaining of a previous admin that no longer exists on the computer) of all single file of the HD ?
Here is a screen shot :
Is the red rectangle it says : "loading... and access forbidden".
When I used the info dialog box of the HD itself and asked to change permissions to items included it did the job on all included folders but not on the files in the folders. It added the new admin permission I changed (removing the incorrect one and adding the correct one : jean-martinbarbut) but didn't remove the incorrect one for single files.
Ragarding the wake up issue it seems to occure when the computer is asleep for a while (more than 15-30 min). If I make it sleep and wake it up 2 minutes after, no problem.