I actually do have some things that are some discrepancies on this. Some information isn't completely accurate, but other than these things, very good write up, and I already know there are more things that can be said in more detail so PLEASE, if you have questions about more detail on things, ask in here or the Performance Q&A section. So here is the issues I've found:
Big Turbos. Garrett and Precision (PTE), are NOT the only ones to make big turbos. Holset, Borg-Warner, Bullseye, Catepillar and Volvo also make large turbos. However, just because the turbo is larger does NOT mean it is looked down upon, as your turbo's response (spool up speed and time) is ALL dependent on the exhaust (turbine) housing size. There are turbos that have large inducers with small turbines so you can get the power of the big turbo with the spool up and reaction as a smaller turbo. Yes there is a small lag time difference, but it's almost not noticeable. Just remember, usually the bigger the turbo, the bigger the exhaust housing because it needs to flow more air to keep the top end power for the turbo at the top of the RPM band. There are more details required to help size the perfect turbo for your applications, but we won't get into that here.
Wastegates - Wastegates actually don't limit the boost, technically. They control the boost by limiting the exhaust pressure in the turbo/manifold itself. Turbo's actually spool from exhaust pressure, thus the more pressure you have in the exhaust (keep in mind pressure or boost is the measurement of restriction), the faster your turbo will spool up and the faster the turbine/compressor shaft will spin, which will cause for more air to flow through the engine (thus making more exhaust pressure). So, to keep the turbo from continuously spinning faster and faster and end up imploding, the Wastegate (WG) actually opens up at a certain pressure (by spring pressure in a diaphram), and allows for the excess exhaust gases to bypass the turbo itself thus allowing for the turbo to stop increasing the speed of the shaft to keep a safe amount of rpms, which limits the amount of boost in a way. Just don't want people to have the wrong idea of WG's, that's all.
BOV location is actually a debated subject. Most people have found that the BOV/BPV/DV should be closest to the TB, not the turbo. The reason for this is if the BOV is close to the TB, it will relieve pressure faster at the TB without having excess boost pressure trying to force it's way into the engine with the throttle plate closed. Having it closer to the TB, does cause boost hang however, but some people call that Anti-lag, where as by time the boost is completely out of the piping, you're already back on the throttle again and you don't loose any spool time.
On the other side of the spectrum, people say the BOV needs to be close to the turbo to help prevent Surging when letting off on the gas pedal. This is actually a valid argument, however, when using a turbo with an anti-surge housing, you don't need to worry about that do ya?
Besides the surging issue, there really aren't any other reasons to have the BOV next to the turbo or mounted to the turbo directly (as the Borg-Warner EFR series turbos have it setup).
That's all I have, but like I said GREAT write up. If you have any questions, feel free to ask here or in the Performance Q&A thread and I'm sure Banker and I can help you out with little to no issues at all.