You may have a risk of this happening here. You should consult with a business attorney ASAP.

I have an offer from a start-up for a C-level role; how much would such a review cost?

Probably a few hundred dollars. A full consultation would be necessary to properly advise you.

How do I know if I have a chance at unlimited or limited civil case instead of a small?

You can run your case by an attorney. A full consultation would be necessary to properly advise you.

Assuming that you are an at will employee, yes, this would be legal.

Do I have a case for wrongful termination?

You may have a claim, if you can connect the pregnancy revelation with the laying off. It would really depend on the exact facts and circumstances...

Can I use a declaration from an expert in leu of in-court testimony?

For the Motion, yes, you can use the Declaration. However, if the case goes to trial, the Declaration will likely be considered hearsay and you...

Discovery from the corporate employees

You can't submit interrogatories to non-parties. You can take their deposition and request documents from them through that deposition, however.

Was wondering is it legal for one business to talk about you to another business

As long as they are not defaming you, yes, this is legal.

Where can I find the name of the owner of a business to file a civil suit?

You can check the Secretary of State's Business Entities website.

Can I get a Court Judgment Against One Cross-Defendant if the Other Cross-Defendants have Already Answered?

Yes, you can and probably should request default judgment against the non-responsive defendant.