1) the EyeTV software does support CC but you lose CC if you export the recorded video to other format.
2) yes ASTC and NTSC (digital and analog) current EyeTV Hybird and EyeTV 250 Plus that was released after MacWorld Expo now support Digital Cable QAM (it has to be Clear QAM) but can't use Digital Cable box so that means the cable has to be connected directly from outlet to EyeTV hardware. Although you can use cable box by using the A/V input and the format will be in SD only so no HD.
both support Analog Antenna NTSC, Analog Cable NTSC, Digital Antenna ATSC, Digital CAble QAM.
EyeTV Hybird does not have hardware encoding and EyeTV 250 Plus has hardware encoding support. That means Hybird require faster mac to do software encoding.
Go to
Compare hardware
and choose Hybird and 250 Plus to compare.
I own EyeTV 250 Plus pre 2008 meaning I can't use it get clear QAM channels but that's okay because I plan to buy later this year a HD HomeRun for that purpose (it has dual tuner so I can use both OTA and digital cable and to watch while recording other channel)
Overview HDHomeRun or
Silicondust