I only use KNOPPIX for "emergencies." I've used Slackware, RedHat, Mandrake and SuSE for permanent installations. I've also installed Debian (KNOPPIX is Debian based), but never used it as a primary platform.
I'd recommend that you use one of the installed distros. You said that you already have Mandrake, so that will do. As to your other questions:
1. If you are using DHCP and a wired LAN, then it will happen without you doing a thing, unless you have some unusual NIC card (I haven't found one in years that didn't auto detect, but in the mid 90's it did happen).
2. You can mount Windows shares using smbclient, part of the Samba package.
3. You will be able use your data to a great extent, but I would guess that any passwords that you had stored in some proprietary application (like Outlook) will not be recoverable simply, and none of the Linux apps will use the Outlook data as far as I know. You can import the mail, I believe, don't know about the contacts and Newsgroup stuff. I hated Outlook even when I used Windows, so I had always used Pegasus and Eudora. Their data was in industry standard formats, including mbox formatted mailboxes, so porting was as simple as moving the files and directories into the Mail directory.
b) Netscape Navigator/Communicator comes bundled with many of the major distros. If not, it is a simple download.
c) Eclipse comes in a Linux version as well, but I like the functions under Windows better. It just "feels" better under Windows (unusual for me).
d) Instead of Excel, you will want to use OpenOffice, or alternately koffice. Both read and write Excel, as well as proprietary spreadsheet formats. OpenOffice uses XML, which is what the next version of MS Office is supposed to do.
e) Various multimedia applications are supported. I personally don't like sound coming out of my computer, so I haven't done much with it, but I have tried audio and DVDs, so yes, it does work. LOTS of choices here, so you will have to decide what you like on your own.
f) There is a Sun and an IBM version of the JRE and JDK for sure. May be others as well. I've used both, but the apps that I have written are so simplistic that I couldn't tell the difference.
g) There are hundreds, maybe thousands, that come either bundled or can be downloaded and compiled on your system. All of the distros come with compilers and interpreters, so you will have a great choice.
h) One of the nice things about Linux is that almost everything that you could want, someone else wanted and built. You may want to start visiting
Absolutely loaded with open source software, most of which will run on your new Linux system.
pansophic