Errrr no. This isn't true at all. Ethernet is totally intended to be daisy chained. That's how the "web" works.
The problem in your post is the wrong use of terminology as well as the use of uncommon terminology. Daisy chaining is mostly seen as something different than how you connect devices to a network. In this case daisy chaining is a network topology meaning that you connect things in series (sequence).
This is not how the web works. If the web worked like that it would mean that only 1 device has to be defunct in order to bring down the entire internet. The internet is set up like a web just so it can avoid this scenario. Only small parts can be brought down, not the entire internet. The web is more like a star-based and/or mesh topology. Networking books talk about star topology btw.
All a managed switch is is basically a miniature computer running DHCP and a TCP/IP switch, so even if poster got a stack he's still just daisy chaining into a computer. The whole internet is just a bunch of machines daisy chained to another.
What you are describing here is a SOHO router. A switch is nothing but a device that connects two ports together. It only has a bunch of those ports (4, 5, 8, 16, 24, 48). A layer 2 switch can even create virtual networks. A layer 3 switch can do some basic routing. Most managed switches are layer 2 switches and thus do nothing with tcp/ip nor dhcp!
Also, a switch general only lays a physical connection. Whatever is on top is controlled by other devices such as routers.
The correct terminology here is devices or nodes, not machines since not everything connected is a machine. Same thing for calling a switch a miniature computer. By doing so you are also saying that a modern vacuum cleaner is a miniature computer. And again, the internet is not daisy chained.
This is one of the reasons the Mac Pro ships with a second ethernet port. It's not uncommon for businesses to pipe the internet into one end of a server, and then pipe the network connection for everyone else out the other.
Not true at all. The only reason a Mac Pro ships with a second network card is for LACP: having a reliable network connection by using 2 network cards. If one fails, the other takes over.
The piping of a connection is not something you do through a server. That's what routers and firewalls are for. They can be dedicated boxes with the same hardware as a server, a virtual machine or special dedicated boxes (special as in specialised hardware that is able to handle encrypted connections, package handling and so on). You're using the wrong terminology here!
That let's you do more managed DHCP, caching, filtering, etc. Again, all totally normal with ethernet.
A device that does this is usually called a UTM but in no means do you need to have 1 machine do all this. Usually they are scattered over multiple machines for added reliability. These services can also be run over other protocols than ethernet.
Performance would be just fine. Maybe slightly/imperceptibly faster than a managed switch due to a better CPU than what you would find in most switches.
That highly depends on the workload of the machine. There is a thread on this forums regarding the Thunderbolt bridge functionality in OS X Mavericks which discusses this. Both are done entirely in software and thus heavily rely on the workload of the machine. A switch works differently. It is not meant for a vast amount of computing tasks, it is only meant to do 1 thing and it does that in hardware. That's why you don't need that much computing power and why switches can be a lot faster than an ordinary computer. The biggest difference is that in case of a computer most things will be done via software which causes a higher cpu usage. A switch has to do it all via the hardware so it uses a lot of hardware offloading. Usually they are faster than a pc. It also shows that it isn't the cpu in a switch that is doing all the work.
So again, any switch you use is still a computer one daisy chains to. All an ethernet switch is, is a low end computer running everything attached in a bridge mode.
They are absolutely not like a computer, not even remotely. A computer is more hardware + software whereas a switch is mostly hardware. They are also designed to do one thing, not doing generic tasks like a computer. Any modern vacuum cleaner could be called a computer with your definition!
Or if you use boot camp, you'll suddenly have no connection.
Bootcamp has nothing to do with that. What you mean here is that any kind of reboot will lead to connection loss (due to the software actually making the connection not being active thus there is no connection being made). When you want to switch between Windows and OS X you need to reboot. IN that case you'll also have to setup the bridge in both OS X and Windows else it will only work if one of them is booted.
A good gigabit switch is $20-$30. With all the time you've spent trying to figure it out in this thread, just buying a switch seems like a better use of your time.
Depends on the definition of "good" but for this case you are absolutely right. A cheap gigabit switch will get the job done with less fuss and time lost than using any computer to do the task. Since the setup is easier it also means troubleshooting is easier and you're set for the future. If you use the second network card you'll be able to connect 1 more device but what if you need to connect another? If you buy a switch you don't have that problem.
This sort of configuration is really for people who want to run the Mac Pro as a server and ensure continuous uptime.
Nope, it is meant for people who think they know networking but in reality have no idea (aka people who implement crappy solutions instead of doing it properly). Anybody who actually knows networking will only do this as a temporary solution (i.e. emergency). Too much work, too much disadvantages to ever use it.
Network cards in a computer were never designed to be used like that. And that is the exact reason why using one for something like this is difficult.
Word of advice: it's fine if you want to dumb down the networking principles but at least use the proper terminology and leave out things that have nothing to do with the setup discussed here (such as dhcp, bootcamp, daisy chaining, etc.). And yes, Apple calls it an ethernet port but in reality it is a network card which is also much easier to understand (ethernet??? network...ah!).
