[TYPO3] :: Typo3 Questions

[Surajit]

Hi List,

Some typo3 questions;

(a)   If we have two sites (domains) www.domain1.com & www.domain2.com 
that I want to use typo3 with.

Is it possible to have one typo3 installation to manage both sites or we 
need to have typo3 installed on each ?

FYI I have two independent websites, and wondering if this is a 
possibility ?

(b)   When they installed typo3 on a test area I setup for them, the 
Typo3 install script needs some folders have write permissions such as 
0777 or 0707. This is also similar for some folders in mambo. Question 
is when this folders are left with 0777 permissions, is there any 
trouble with security, since anyone can access? What do you think when 
these folders are left this way? Especially for a normal open public 
site as opposed to the current one we're working on, which will be an 
Intranet.

Thanks
Surajit