I'm not an expert in how the State Department handles issuing security clearances or law. I am going to limit my responses strictly to your technical inquiries and Bryan Pagliano's qualifications.

I am going to attempt to remain as impartial as possible while writing these replies.

What was the background of those who set up Hillary's communication system (ie: education, experience, security background, etc.)

Bryan Pagliano attended Emory School of Business where he received a BA in Political Science. Following that, he went to the University of Maryland - Robert H. Smith where he received a Masters Degree in Business Administration.

His Linkedin profile claims that this was in a graduate program that encompasses "Business Administration, Finance and Technology", but I see no such program listed in either University of Maryland's or Robert H. Smith's specialized list of graduate programs.

Based on this information, I don't believe Bryan received any encompassing formal education relating to IT. To be perfectly honest, this isn't unusual within the technology field. I have worked with competent systems engineers who majored in dance, and skilled programmers who learned autodidactically.

Would we trust those involved to have managed any other significant secure or sensitive network?

While Bryan was receiving his education at University of Maryland he was employed as a "Systems Team Lead" and was promoted to "Systems Engineer" at a company that did third-party (read: outsourced) IT in Washington DC. Following that he went to work for Hillary Clinton's 2008 campaign as IT director. Upon Clinton becoming Secretary of State, he was offered a job on her staff as a "special advisor." This is important, because there is no official record of Bryan being employed by the State Department in any kind of IT role.

All of these fancy, nebulous, indescriptive titles can seem daunting to understand to people outside of the industry. However, all of the job duties from all have one thing in common: those that hold these positions are responsible for the installation, security and maintenance of hardware/software assets of an organization.

The responsibility I'm describing is an incredibly broad one. It is a very vast industry with a great deal of specialization. Generally, sys-admins/sys-engis work on teams with employees specializing depending on the environment. Hillary's email/VPN servers would be a Windows Server environment, where a typical team would have a skeleton crew of a network specialist (routing/switching), hardware specialist (data closet, NOC) and a windows administrator (AD/DNS, etc.) A robust team would also include an automation specialists (programmer/scripter) and a database administrator (T-SQL/Oracle[etc.] scripter, DB configuration, etc.) Obviously, people can hold experience and expertise in more than one field of study, but it's very, very, rare to encounter someone who holds them in all.

I have seen no reports indicating that Bryan worked on a team. Bryan could have very well set all this up by himself, or with a small team of contractors, in Clinton's New York residence. Again, though, I question his competency in every area. Port 3386 (Remote Desktop Protocol) begin open in the DMZ is the most damning case against him. There's certainly other things that raise questions, however. Why was the certificate self signed for the SSLVPN? Why was there a 3 month lapse in encryption, and was OWA/IIS open via the DMZ at that time? Why was Bryan unaware that Platte River was creating, I'm guessing, full disk backups?

Would she have known if her communications were appropriately secure?

Extremely unlikely. Although I am not a legal expert in this area, I believe it would be safe to assume she accepted that risk when she decided to use these resources rather than the ones provided/secured by the State Department. She is still responsible.