to install or not to install

[QBA <jakbyto@kki.net.pl>]

Hi,

I'm gonna install Debian 2.2 on my computer soon (now running RH6.2)
and hope that will handle this task but I'd like to know one
thing about installing new programs. I've been browsing through this
list contents and learned that Debian has tools letting me make
deb packages from tarballs or rpms (and source packages too of course).
But I don't know if it's really useful and needed. I must say that
I have a bad experience with rpms. Installing them is trivial
but configuring program after installation is a mission impossible.
So when I have a choice to install tarball or rpm package I always
choose tarball. Following instructions included in INSTALL file
gives me certainty that the program will be well installed and 
configured. And there is also a second reason to install tarballs -
some cool programs are available only in this format (e.g. w3mir).
And here's my question: is it a bad idea to install tarballz on Debian?
Thanks for help,

QBA

PS.
I read that APT (mostly apt-cache) needs 2-3GB /var partition. 
BTW, what does this program need so many bytes for?
When I add to this some space for cached websites and posts from usenet
I'll get about 5GB /var partition (it's a half of my disk size!).
Is it really necessary to make this partition so big?