Safe-mode loads minimal set of drivers so on some program files avast will have access that it may not otherwise have.It might run faster too
Max, I'm not so sure. If you're talking about cleaning and repairing a file, ok...
Maybe the on-demand scanning too...
But, detection should be the same... On contrary, we will be in danger because the virus would infect the system in normal operation because on-access wouldn't detect the virus.
Speed of scanning, ok, safe-mode could be fast!