While I'm sure you could enjoy a new Sam, let's correct misconceptions in your list as to why:
>Advantage of doing this change:
>1) No viruses ever on my computer
>2) No more stupid malware
Just because you aren't aware of any such things today doesn't mean there aren't or won't be such things in the future, specifically if its Internet enabled. web browsers and their javascript engines can have security issues that don't depend on the underlying OS and CPU type.
Unix based codes might not have proper security checks when running in an Amiga OS type environment because some hacks were made to quickly port the code and security testing lacking because the original code expects the OS to behave in ways that are common for Unix but not for an Amiga OS. You only feel safe because the small market share doesn't make you the most tempting and lowest hanging fruit to compromise.
3) Faster speed boot time and response time to applications
OK, that may be true.
4) save in my electric bill as I am using 400+watt power supply but the SAM 460 need only 100 watt to run. Saving a lot in heat and energy.
The power supply wattage isn't what it consumes on a constant basis, it is what it can put out dynamically if necessary. If your cpu, disks, gfx card are low power you'll never come close to dissipating 400W by any part of the system. Many PCs ship with overbuilt power supplies because the vendors don't want someone hooking up all the most power hungry components they can imagine and blowing it out.
