I can't give you a secure answer but I think that the node is chosen randomly (but I'm not sure).
No, if you run the latest version it will download from all available peers (after it has the headers). https://bitcoin.org/en/release/v0.10.0
Which node you download from don't matter much anymore. The speed issue is a thing of the past, thanks to the headers first solution.
As such I also expect that the QoS / Netlimiter issues are a thing of the past (unless somebody connects to your node only on purpose of course).
interesting, I think I'll put that to the test later, re: connecting to default 8 nodes and see if I receive blocks fast enough. it'd still be slower obv if I couldn't get at least 6Mbps from all those connections, since that's about what I max out at when I synced with my server (was around blocks 150,000-250,000.. before and after that it was slower)
Please report back with an update, would like to know how it goes.
Don't particularly want to do it on my home computer, but I'm getting a new dedi within the next week or so, so I'll test it on that. Normally it takes about 2-3 hrs on an i7-4770 (connected to one IP)