Actual infinities.

[Jehanne]

Aristotle believed that God and the Universe were co-existent with a beginningless past.

Precisely.

Earlier you said arguments against actual temporal infinities are not helpful to theism, but they aren't necessarily harmful either.

They are neutral; agreed.  But, as Professor Sean Carroll said repeatedly in his debate with WLC, theism is 1) not well defined, 2) given to multiple definitions, and 3) leads to no strong predictions.  Theism is compatible with everything!  As with the idea that planets move because there are angles pushing them in a way that conforms to mindless natural forces, so, too, Occam's Razor demands that we reject theism, deism, pantheism, etc., and only accept naturalism, as there is simply no need to postulate anything beyond the natural order.