Explain to me why Linux is bloated? You can disable nearly all features and end up with an extremely small kernel.

ABox does not support memory protection.
You can not create kernel threads in ABox (?). New threads run as user-level processes in ABox.
ABox is an AmigaOS API wrapper whereas QBox will be the real MorphOS API.

The reason applications are so fast in MorphOS is mostly related to the fact that these applications were written to run on m68k. I don't see why larger applications would run significantly faster on MorphOS than any other OS. GCC for instance runs significantly slower in MorphOS than it does in Linux.