If I use 3D models from DiscMaster but create the animations (running, jumping etc.) myself or get them from a resource like Mixamo, is my entry still qualified for the Spelunker category? I don't think there are any of those on DiscMaster (or at least I don't know how to find them), so it'd be good to know.

Yes, if DiscMaster doesn't have something like animations, then you can make it yourself or find it from some other resource, and qualify for Spelunker. We've now updated the FAQ to mention animations. Thanks for the question!