XeNTaX

I've been looking at prepping some free models for printing online, some of which are pre-rigged. For unrigged, simpler models I've been using Mixamo which works fairly well(though annoying it doesn't export static frames/have more static poses). When it comes to complicated models of characters with different movable parts, I'm at a loss of what to do. Do I just have to manually move everything or is there a way to download existing animations/poses in something like blender and make it try to fit the rigging?

Also any other free/simple programs for simple rigging would be nice too, since Mixamo does lack static poses(and the female poses are godawful).