1. HDMI-ARC works for internal sources such as ATSC/QAM tuners or Internet content with multi-channel 5.1/7.1 output (in some format either DD, DTS or PCM?). I know from reading the FAQs on ARC (hdmi.org) that it technically supports up to 8 channels of audio (7.1).
2. HDMI-ARC does not pass 5.1/7.1 multi-channel output from external sources (Blu-ray, Cable/Sat, PS3/Xbox). Rather the TV will only support 2.0 or possibly 2.1 PCM from these external sources.
Are these two items correct?
In regards to Summary #2 above: I can understand a TV not having decoders for all HD audio codecs. However, can you not send multi-channel PCM from your Blu-ray player to TV and that same PCM be sent on unchanged to your AVR using ARC? Otherwise, do the other HDMI inputs not support multi-channel PCM or other audio codecs?