That file is definitely FCP-X and probably won’t open in 7. Internally it is XAVC 50 mbit, and decodes fine as XAVC, but Shane is right. The fastest way is to get the camera original.
The MCC has no default size, so you may want to try adjusting your project settings before importing. In general, the MCC is associated with 1080p/i or 720p, and SCC is associated with PAL/NTSC.
I don’t believe we can set the number of lines to use from a subtitle to a caption format, but it’s something we should probably add. For a sidecar, it would really depend on the target player. WebVTT is nice and standard, and would work with most web based systems. MCC/SCC and others will work with more advanced players, but not the web ones.
You could try converting the SRT to an MCC, and then import that input Premiere. We have a beta converter online that’s free to try, if you want to give it a go:
DrasticPreview will read the AAF data track directly and display it and also read the output files and display closed caption overtop of the video. Full disclosure, I work for Drastic
Its not uncompressed, but I am huge fan of Camtasia. It does an amazing job and even comes with a ‘screencast’ dedicated editor that has all the nice little arrows, highlights and fly outs. No fuss
All the C300 footage I have seen only has 2 channels embedded in the MXF file. Have you checked it with MediaInfo? If so, the MediaReactor AMA plug in should read up to 16 channels of audio in an MXF. Its free to try: https://www.mediareactor.ws