Well I have updates about AcerAspire 5520!
The SATA problems remains so I chose to install in external USB HD. I used kalyway dvd installer, with minimal specs for install (kernel sleep, smbios default by netkas, amd patch) and bingo!
I got it! OS was installed correctly, restarted with -f at boot prompt and there it was the os welcome movie!
Some tweaking is required now:
-internal SATA HD and DVD-CD drive are not detected
-no audio
-no internet
-resolution set at 1074x768 when it could go to 1280x800
The first pbm is the most relevant as I need DVD-CD drive to access iDeneb DVD installer for some kext I need now that is included there ... keep looking for info and trying! any tiny piece of advice is welcome
My hardware report is attached