Casper questions for managed environment

Hmm, I am not a complete Casper neophyte, I've used it in the past with another entity to create and deploy images. But I haven't used the admin part of it to manage environments, so that's one thing that I am especially interested in at this time...

First off Welcome!

I'll try and answer some of your questions:
For partitions, create a smart group on your jss. (you can find this url by going to self service(on your local machine) and seeing what it says on the left hand side. Should be Something.yourcompany.com)
Login to the web interface through Https://something.yourcompany.com Go to Management settings
Click Computer Management
Then Create a Extension Attribute with:

#!/bin/sh

#
# Using diskutil list to check for 
# disk partitions reporting as 
# "Microsoft Basic Data"
#

BOOTCAMP_DETECT=$( /usr/sbin/diskutil list | grep -c "Microsoft Basic Data" )

#
# If Microsoft Basic Data partition is
# reported by diskutil, script reports
# "Yes". If no Microsoft Basic Data partition
# is reported by diskutil, script reports "No".
# 

if [[ "${BOOTCAMP_DETECT}" == "1" ]]; then
      result=Yes
   else
      result=No
fi
echo "<result>$result</result>"

exit 0

This will search for boot camp partitions.
Then create a search based on the criteria of bootcamp partition is "Yes" this will take a bit of time to propagate as it runs on the next machine checkin.

Would there be an instance of a Casper "server" running?
Yes this is called the JSS
I also know that the images were loaded onto some machines from a USB drive, so I am not sure that there was a network piece to the deployment.
Typically you'd build a base image, and deploy it using casper imaging through either a netboot, firewire or thunderbolt. A example workflow is Here

You may have already done this, but please find out with your technical account manager is and get in touch with them to explain the situation. They can help you do some detective work to figure out the basics of your environment and get yourself up to speed.

You also may like this talk, "Don't Panic, what to do when your Casper Admin Wins The Lottery from JNUC 2014.

Second, feel free to get in touch in a realtime sense with the JAMF Nation community via Slack or IRC.

If you running dual boot labs you will probably find the Windows side was deployed using one of the two following methods.
1: Out of SCCM or other Windows deployment using USB boot media (might be where your USB reference comes in) although this requires careful Task Sequences to ensure they are not messing with the partitions and deleting the OSX side.
2: With Winclone images using a tool from these helpful fellows https://twocanoes.com/products/mac/winclone

You will also definitely wanting to look here http://www.jamfsoftware.com/training/ for the next training course in your area, they are well worth it.
Also here http://www.jamfsoftware.com/resources/product-documentation/ for the various administrators guides etc...