seniority systems quite well, I understand the resentment of your co-workers.

Are the managers also union?

Management needs to make it clear exactly why they are doing this for you. Perhaps you can give up something else to make those senior to you a little happier. Like always working some shift that is undesireable but you can work, given your school schedule.

Although quite a few of them are former union members who had to leave when they were promoted. Most of them have a good relationship with labor. It's really corporate that everyone distrusts (including most of the managers).

That is an interesting thought, although the industry we're in has very few "undesirable shifts"... It's the transportation industry, so the hours are all over the place. You might not imagine a 4AM morning shift is desireable, but in this company it's highly sought after. There's a lot of subjectivity as to which shifts are "good" and which are "bad". People try to work shifts that fits their personal lives best.

Fortunately for me, the shifts most of my co-workers wanted, such as very early morning, were ones you probably couldn't pay me enough shift differential to be willing to work.

So what are the least sought after shifts? Can those work for you?

And I've told them that I'd be more than happy to work those shifts if that's what works. As of now, it looks like that agreement will allow me to keep the job. To be fair, it's only a couple people who raised objection. I have several friends of varying seniorities in the company, several of whom seem to be advocating for me.

And being willing to work the least popular shifts is huge. Depending on your experience with shift work, you may need to trust me on this.

That might help your situation.

However, what I study in school directly relates to what the company does, and they have a history of trying to get students like myself involved. Working as a standard employee now might lead to an official internship in the near future.

Interns are non-union, along with managers.

if the union doesn't want to file a grievance they don't have to...so you need to talk to the union leaders and the folks who have seniority.

If the management make an exception for you, it may cause all sorts of problems down the line when management wants to make exceptions for their friends, favorites, relatives, etc. The management might offer exceptions to some employees to undermine the union, or establish a history of exceptions that weakens the contract.

You may have a good reason for an exception, but maybe you can't trust the management once there is a foot in the door.

If you talk to the union leaders, they can explain how they see the exceptions. Some contracts are hard-fought and are necessary to protect the group, so exceptions cannot be taken lightly.