The mini has 'true' optical out. Mini-Toslink is Toslink, so it's just a matter of buying the right optical cable.
DD/DTS 5.1 is a limitation of Toslink. If you want 7.1 or the newer lossless codecs, that requires HDMI or an conversion to multichannel analog audio on the device (some HD-DVD players did this, back when that was still a thing :)
That is correct. Hence my gripes towards the mini - it wasn't designed to be a digital media player, whereas the AppleTv is (HDMI, optical out). If it supported 1080p and was open, it would be the device. The boxee box could have been the device, but now I am going to wait for the logitech device.
DD/DTS 5.1 is a limitation of Toslink. If you want 7.1 or the newer lossless codecs, that requires HDMI or an conversion to multichannel analog audio on the device (some HD-DVD players did this, back when that was still a thing :)