Hooray! Fixed my crushed black levels. Turns out that since I’m outputting using an AVC codec, it assumed studio levels, so automatically applies a studio to computer levels filter. So I just had to undo the manual application of the filter. I’m uploading that clip to replace the other one, it’ll be in my tracker about 15 mins after posting this message.

On to the framerates. If anyone has the slightest idea why the following might happen, please point me in the right direction:

Mediainfo reads the original source mkv files as 23.976fps
Mediainfo reads the ripped mp4 video files as 23.976fps
In the media window of Vegas Movie Studio when selected, it recognises the files as 23.976fps (VFR?!)
When I check the file properties in Vegas, it recognises the files as 25.000fps (greyed out)
When the project settings and ruler are at 25.000fps, the frames align to the ruler
When the project settings and ruler are at 23.976fps, the frames do not align to the ruler