1.

There is notification settings, you can use it to set notifications to each channel
All- gives you a notification everytime someone comments in a channel 
Mentions- gives you a notification everytime someone pings you (@yourname)
Nothing- you dont get notifications at all

2.

Pinned messages, useful info 

3.

Description of a channel you are currently in

4.

mutes channel

War-room (Mentions)

you can ask anything game related (mechanics, tactics, etc)

Red-star (All/Mentions)

here we gather for redstar runs(rs)
it works like this, you want to run a rs6 so you write @RS6 and it will notify all people with RS6 or higher 
then ingame click on you red star scanner, switch from public to private and start the search, others will be able to join you throught corporation's chat
arts on private red star will have %bonus to its value after researching (more credits, hydro, blueprints)

Blue-star guide

tips and tricks

techbot guide

basic guides, can be found on this web too

Techbot (Mentions)

techbot - more infomation here

WS-guides 

information of how we do whitestars, read it so you can understand orders given to you 

Battle-annoucements (Mentions)

WS battleplans, layout and toons are posted here

Battle-summary (Mentions)

Commander of recently ended WS writes about events that happened in said WS, giving his opinion on it and saying what could be improved

Ship-memorial (Mentions)

Keeps track on ships that nobly died in pursuit of victory, most useful information is time of return of destroyed ship

General-discussion (All/Mentions)

Here we discuss plans, ideas, tricky situations etc currently happening in white star match
if you are very interested in WS i reccomend turning on all notifications

Orders (Mentions)

Orders for you what to do in current WS

Dump-n-grap

Orders for you on miners and transports

Rocket-support

orders for players on rocket support