Just a note, for flash-and-reboot, you do not need to be root. Nokia installs a sudoers file which allows flash-and-reboot to be run via sudo and the flash-and-reboot script has a section at the top that will relaunch it using sudo if you are "user".

But I have the feeling I'm going on here as you need to be root to use dpkg for the 5th step as you know

But you can shave 1 seconds off by making step 2:
2. Start a terminal

:P

Anyway, I'm done with just a simple kernel like this :P. I've been working on this:
op_mode patch, rotation patch, brightness changing patch, 48Mhz mmc, japanese radio patch, musb fix patch, preempt, usb powercheck disabled, OTG whitelist disabled so everything works, menulaus setting voltages messages removed from dmesg, eac mode, play enabled, record disabled messages removed from dmesg.

Except for the preempt, and the eac mode patch, the rest is all patches and work by other people