ssh2 and non-stable

[brew@theMode.com]

Is it safe to run the non-stable software package ssh2?  Can I safely use
apt-get to install it on my Dell laptop?  I guess my question is really -
does non-stable mean it is unsafe, or just not garanteed to be safe.  
Will an apt-get installation still check for conflicts and dependencies?

And what do I put in my sources.list to get it?  I tried adding a source
suggested on Usenet, but apt-get still could not locate and install ssh2.

I've successfully installed and am running ssh, but one of the servers I
connect with requires Protocol 2.

Thanks.... not only for any help with this but for all the help I've
gotten reading this list since I started running Debian in August. I'm
slowly learning little by little thanks to you guys!  I use Debian on my
laptop as a portable web site development platform using Apache, perl, and
various SQL databases.

Thanks,

brew