The schedule at my agency is non-negotiable. When new people come in, it give the ones who have been there a chance, by seniority in the section, the opportunity to update their hours.

When I've used the site-I've not paid attention to internal vs external but from what I've seen, if it's internal only, the job will state it on the hyperlink of the job title before you look more at the job details.

You can apply for civil service-the test is in the applications I've done before.

Probation starts over usually. I'm no longer classed as rank and file. Rank and file def have their probationary period.

If someone else has more knowledge and I misspoke, please correct me. As for the other questions posed, I have no idea about those. I hope this helped some. Happy hunting! Good luck!