"hostname" question during Debian installation

[Martin T <m4rtntns@gmail.com>]

During Debian installation there is a question about "hostname" using
expert installation mode.

Am I correct, that "hostname" inserted during Debian installation is
associated with a local(address from 127.0.0.0/8 range) IP address:

<<<<<
martin@martin-ThinkPad-T60:~$ hostname
martin-ThinkPad-T60
martin@martin-ThinkPad-T60:~$ grep martin-ThinkPad-T60 /etc/hosts
192.168.1.67	martin-ThinkPad-T60
::1	martin-ThinkPad-T60	localhost6.localdomain6	localhost6
127.0.1.1	martin-ThinkPad-T60
martin@martin-ThinkPad-T60:~$
>>>>>

..and it's used by few software programs(for example Apache, MySQL),
but hostname is usable only locally and not reachable from any other
machine even inside the LAN? In addition, aren't most of the programs
using 127.0.0.1 address which is mapped to "localhost" in /etc/hosts
file not to hostname I set:

<<<<<
martin@martin-desktop:~$ sudo netstat -lnpt
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address
State       PID/Program name
tcp        0      0 127.0.0.1:8118          0.0.0.0:*
LISTEN      1233/polipo
tcp        0      0 127.0.0.1:631           0.0.0.0:*
LISTEN      1057/cupsd
tcp6       0      0 ::1:631                 :::*
LISTEN      1057/cupsd
martin@martin-desktop:~$
>>>>>

If yes, then changing the hostname shouldn't break any
services/programs associated with it?

All the explanations and clarifications are most welcome!


regards,
martin