Post installation

A few months back I started looking at Drupal as a successor for the forum system I use on a site I run, and began investigating the access control permissions for controlling access to the different forum sections. I looked at various modules and built-in functionality, but came away a bit confused. Then I left it (as mentioned) for a few months and have only just begun to pick up the threads.

It seems that in the intervening months new versions of Drupal have been and gone, and versions of the modules I had in use have changed. I intend to start again from scratch, but I'd like to be certain I'm doing this the right way from day one. So, without further ado, here are my requirements:

1. A group-based user system, whereby individuals can be assigned as members of one or more groups
2. A variable-level permissions system for groups, which can assign the permission to (at various levels) edit posts, write posts, read posts, see forum categories

Essentially, for those who are familiar with it, I want all the flexibility of phpBB's permissions system (apart from the 'user' level permissions) such that sections of the forum will be completely invisible to guests and registered users, others only accessible as read-only to certain groups, and others still essentially invisible to everyone except a specified group.

So what would be the best way of going about implementing this system? I would like to use as few modules as possible, so if this is possible with out-of-the-box Drupal now that'd be smashing.

I have nearly 20 distinct types of events in a non-profit community and decided to use taxonomy terms instead of flexinode for reasons explained in this forum posting.

I am slightly confused about the right way to build the taxonomy because each event type could apply to three types of participants (the faciliating non-profit, the member non-profit and external non-profit). Could someone please guide me about the right way to do this?

Vocabulary: Events Section
Terms:
-Main Orgn. Events (actual term would be just the name of the faciliating organisation)
-Member Events (actual term would be just "Members")
-External Events (actual term would be just "other")

Sample of event types:

1. Meeting
2. Inauguration
3. Conference
4. Seminar
5. Workshop
6. Course
7. Fund Raiser
8. Award
9. Public Hearing
10. Interface
11. Annual Day
12. Book Release
13. Grant Release
14. Medical Camp
15. Exhibition

Do I put all of this into the same vocab? I can't imagine creating all the 20 event types as child terms of the 3 main terms (20x3= 60 child terms).

I initially thought I only wanted the following urls:
www.mydomain.com/event/orgn
www.mydomain.com/event/members
www.mydomain.com/event/other

but, with pathauto, I am also tempted to have urls like these:

www.mydomain.com/event/orgn/event-type1....to event type 20

I have a flexinode type "Article"
I also have a couple of index pages for articles that are themselves Pages

I would like to display a block on all "Articles", and also on the index pages. Does anyone know if this is possible?

The problem arises because if you tick the "Show only on article" button, you then cannot use the "show only on specific pages" section to specify non-article pages to show the block on.

Taxonomy_Context doesn't appear to be sufficient because I want to display a custom block, not the context block.

I’m looking into setting up a recruitment website and want to set it up so that users can log in to view jobs that are relevant to them based on criteria that they've selected i.e. location, salary, job type etc. If possible I'd also like to set it up so that the system notifies them by email if a job meeting their requirements is added to the site.

Which modules would be relevate

Please understand that to a non-coder, the existing instructions on what page and what part of the code to replace with the flexiblock php (I've read them all) are clear as murk.
What I want: using Marvin i want to set up the blocks in the main text area of the page to line up across and down like tiles. In other words, I want the blocks to be the page (using Front Page for the intros).

Is it possible for users to edit other people's content?
One of the features I'm after is a wiki-type environment.
Am I right in saying that drupal's "wiki" module is only for allowing wiki syntax to be used?

Can anyone advise me? I need to make a decision for a client asap ;-)
Thanks