04-17-2012, 02:30 PM
Wow, I remember the days of having to deal with all that stuff. You just reminded me how low-maintenence OS X is... I never really think about maintenance.
Apple doesn't say that Macs NEVER crash or have problems but there are significantly fewer of them, and none of them are going to ruin your computer. The Registry is one of the biggest drawbacks of Windows and defragging never seemed to do anything but take a long time to finish.
Deleting apps on a Mac usually just involves dragging it to the trash, though if an app comes with an uninstaller, it's best to use that. Little preferences files do get left here and there, but as mentioned, they are totally inert and don't take up much space. But if you want to really keep things clean, you can download App Cleaner, which deletes apps along with all any little files left behind.
In addition to Disk Utility for verifying and repairing permissions, you can download Onyx, which does these things and more, such as clearing caches. It's free, and you should only need it once every few months, depending on how you use your computer.
Others had good tips about sandboxing but everything else on your list, I've never experienced anything like that on a Mac ever!