After replacing the tie-rod and bellows boot, the steering wheel was rotated left + right: wheels moved as expected. Is there any other simple test that could / should be done?
No - that's all you need to test. Now drive the car to a nearby garage and get them to do a front-end alignment on it - you won't have gotten everything exactly where it needs to be, so let them fix it to specification.
As an added bonus, it puts a fresh pair of mechanics eyes onto your work, so after it's been aligned, you know that everything is good.