on startup the wallpaper appears with all program icons , then it take a white before all icons grey out
then more time to have them reappear, then grey once more before they come back and one can start using the programs
You can disable ALL startups - except the AV program and those that you might have set yourself - e.g. a dock or the sidebar (gadgets).. Nothing bad will happen if all those startups are disabled. They wil start when needed.