I don't know all the answers but I'll answer the ones I know.
>
> 1) I found pkg_add and pkg_add -r to download and install files like 'apt-get
>install' on debian. How can I do an equivalent of 'apt-cache search'? Ie, how do I
>get a listing of files based on a search criteria?
>
try:
man ports
for that question
> 2) Shift-Pageup/pagedown to scroll through console history is great on linux. Can I
>enable this on FreeBSD?
you can install bash and set it as your default shell
> 3) I (foolishly) accepted the default 'partitioning' of freebsd. It's not really
>partitioning they say. I made a real 4GB partition. Then the installer created some
>logical units inside of this partition. / is 50mb!! /var is 20mb and /usr has all
>the rest. Is there a way to dynamically change this? Or how can I manually change
>it without reinstalling? Already I'm running out of space on /.
>
> 4) I chose the text-based freebsd daemon screensaver. Pretty nifty. During install
>there was a nice program that allowed me to configure various options, install
>packages and other things. How can I recall this program without booting off of my
>floppies
as root run: /stand/sysinstall
this will let you use the slice editor which would be how to deal with q3
and q5, be careful read the docs, you safety is not guaranteed
> 5) How can I mount my linux partition? I have freebsd as a primary in /dev/hda1.
>Linux is in an extended (/dev/hda2). Linux root is inside there at /dev/hda7.
>Looking at my devices I only see some /dev/ad.. Since my freebsd (hda1) is ad0s1,
>I'd figure linux root is at ad0s7, but I only have ad0s1-4. Is there a way to get
>freebsd to open up that ad0s2, to get access to a logical inside of a primary?
>