Unlike Bluehost, where any updates and access to PlugIns, etc are easily done, what happens when WordPress is downloaded directly onto my company's server? Am I to rely on my IT guy to install updates?
No. If you have an admin account to manage the *website*, you would only need the IT guy to do things such as I might have to go to BlueHost (in my own case) to get done. It matters not where the servers are located, just whether or not you have an admin account for the actual site. However, your servers will have to meet the criteria made available http://www.simplescripts.com/articles/simplescripts_system_requirements at the link I posted.