About "Under the Yoke", it's already in my list on the first page, though here's
a single YouTube link instead (I'll edit it there too). And while searching for it, it seems there's also a 1990 series about it, which I haven't watched - here's
the first episode, I'll list the others in the first page. Unfortunately, both are only on Bulgarian.
As for movies about Gotse Delchev or Yane Sandanski - the only one I can remember which is near it is "Mera spored mera" (listed on the first page as well). But I haven't watched it, so I'm not sure if it includes Delchev and Sandanski or not, I only remember it's about that general time and place (Macedonia around the Ilinden-Preobrazhenie Uprising, 1903).
Otherwise, I can't seem to find any subtitles for "Kapitan Petko Voivoda" or "Geroite na Shipka", be they Bulgarian or already translated (there are some BG subs for "Geroite na Shipka", but they're only of the Russian speech).