I don't see why number 2 can't be done on any other distro. Nothing is stopping you from compiling your own kernel on any of them. Of coarse its rare that people would bother.

3 is also a feature of Arch. The problem is now you have to spend time setting that stuff up. More problematic is you have to actually know you need to set something up. Did you remember/bother to tweak, your ssd settings in fstab? Setup OpenAL for 3d sound? Your HDD IO schedular? Your TCP buffer settings? Your font renderers antialiasing? All that crap sould be taken care of (although admitidly distros don't seem to do things like setup SSD schedulers to deadline/nop.

1 seems a be redonculious. There is very little reason to really worry about having a few extra packages lying around as long as there not running stuff in the background. I think it's more for people with a case of OCD about their file system.