Yes, I believe all of the talk channels are streamed @ 48kbps. And in regards to the captcha/timing out issue, if i'm not mistaken uSirius bypasses that. It is what people have been using to stream sirius to their iphone.
Basically what it does is it gives you a stream of all channels so for example the howard 100 channel would be
http://192.168.x.xxx:19080/asx/asx?b...0&r=1199594576
I pretty sure it's possible to listen to an internet radio stream in RR(haven't needed it so I don't know much about it) but it would be somewhat easier if this were somehow integrated into RR such that you could enter your login details in the config and be good to go, provided you had an active internet connection.