The good news is that you can almost always get the bandwidth and throughput you want, as long as you're willing to spend the money. The relationship between throughput and cost is roughly linear - the more you have the more it costs. Stability refers to how often the system is down, either unexpectedly or planned. The telecommunication industry rates stability by a scale of nines. I doubt anyone in student affairs needs a four nine system, but a two nine system is worth shooting for.
Scalability characterizes the ability of a system to grow to meet demand.
We generally talk about it in terms of the number of simultaneous users that can be handled. A scalable system will allow you to build an installation that can handle 10 users but easily expand to handle 10,000 without having to redesign the whole system. Location of infrastructure describes where the system is physically, as well as logically, located. While this can be a great solution for schools with limited infrastructure resources and expertise, there are some very real issues that need to be addressed if you choose to have parts of your infrastructure located off campus. As with content management, a full discussion of these issues will have to wait for another time.