1. Will the Linux machine be able to easily access my home NT based file sharing network?
No, not easily. Look up something called "SAMBA"
2. Will i be able to connect to the internet using Windows ICS?
Yeah, no problem here.
3. Are there third party driver writers for Linux as i believe Acer/Ali have no Linux drivers for any of my laptop hardware or will mandrake have these or will generic ones work?
Well, for the most part every driver written for linux is a third party driver. You'll have to check the hardware compatibility database on mandrake's site, which I have happily provided a link to : http://www.linux-mandrake.com/en/fhard.php3