> It requires slightly more complex firewall rules, and asking the network admin to put them in place might raise some eyebrow for reason 1

Well, in many such situations data is provided for free, putting huge burden on the other side. Even it it's a little bit less convenient it makes service a lot more sustainable. I imagine torrent for free tier and direct download as a premium option would work perfectly

I wish... I overpay more than double market value for my connection, and am not allowed to configure my router. This is the norm for most apartment dwellers in the US as far as I'm aware.