physical mac address

[Micha <codejodler@gmx.ch>]

Hello,

Am i right that locally generated traffic never has a MAC address (besides
00:00:00:00:00:00:00:00:00:00:00:00:08:00 ) even for traffic from/to the
 own 'external' IP, that is, the physical NIC attached to the gateway 
(like, eth0=192.168.1.2) ? It never can be sniffed, for example ?
If i send to 192.168.1.2, what happens in the kernel router ?
And is there any significant difference to 127.0.0.1 traffic ?
Just curious.
The questions come to my mind when i puzzle why not setting up 
the hostnames (and aliases) like 

127.0.0.1         weird          localhost
192.168.1.2    weird.domain

though it's not recommendet. But maybe it eases filtering (you know
that weird.domain is always external traffic) and offers some
prevention against fixed pathes of trojans ?


 m°