Pre-installation thoughts

[tsr <tsr.offentlig@tsr.se>]

Hi,

So, I want to completely reinstall the OS:es on my main computer and I
would like you to review and comment on the idea outlined below.

(I've used Ubuntu before but I find that it moves too quickly and is not
as stable as I remember debian from before, plus I like the debian
philosophy more)

I have a pretty clear picture of what I want to accomplish, but I know
almost nothing of these things and the information I've found[1] is
written like I already know some things.

What I am asking for is both critique on the idea itself and information
on how to accomplish it.

My plan:
- Partitions (160GB disk):
  - (10-20GB?)  bare minimum for OSX (firmware upgrades, efi)
  - (30-40GB)   base debian system incl. /home/*
  - (100GB)     public media files
  - (10GB)      encrypted partition for my home.
- Users:
  - me, with sudo and the encrypted home with extra password to
unencrypt.
  - others, with the following capabilities:
    - passwordless login (with 3 possible locales)
    - connect to internet (wifi/lan)
    - run iceweasel
    - play music and movies from the public media library 
    - play a selection of games
    - run a terminal with ssh (for my cli-enabled-friends)
    - run OO and use the printer
    - no ability whatsoever to tamper with the rest
    - auto-logout after 30 min inactivity
    - cleaning up on logout - browser, document history, high-scores...
- Other stuff:
  - I want the ability to easily switch 'modes'
  (I am not very organized and I tend to mess things up so I want these
to be clearly separated but also easily switchable, therefor I've
thought of using virtualization - but I'm not sure if it is the right
way to go. It is important for me to have a 'clean' base install but
still being able to install lots of random stuff when I want that can
easily be purged)
    - day to day desktop (mail, browser, text, calendar, etc)
    - LAMP-hacking
    - other web-hacking (with other instance of apache)
    - general hacking (python, ruby, gtk

Slightly specific questions:
- guest user
  - how do I set-up the guest user?
  - umask 027, and the chmodding the neccessary? but how do I access
everything?
- 'modes'
  - is virtualization for me or are there other/simpler ways of
achieving what I want? (with regards to my 'modes')
  - if virtualization is the way, where do I make space for the images
(is that even the correct term)?

Hopefully,
tsr

ps. I'm not a member on the list but I will check out the archives, so
no need to cc me.

------------------------------
[1] I'm thinking of things like:
- http://wiki.debian.org/VirtualBox
- http://www.debian-administration.org/articles/577