I've got a compost can sitting out on my patio, no worms, starting to
decay, mold, etc.

If I used this to prime a vermiculture bin, would I be harming the worms
with the mold?

If I used this to prime a vermiculture bin, would I be harming the
worms with the mold?

I don't think so. The mold is what the worms eat (along with bacteria
associated with the food breaking down).

If you want to play it safe, you can add the compost-in-progess
gradually (after starting the worms with newspaper or whatever they
suggest as the "starter" bedding).

But we've never been highly particular about our startup process, and
things have generally seemed to work out (we've killed a few worms,
but those were pretty clearly due to too much heat or too much cold).