The North Dakota Secretary of State has a free business search. Also shows companies which have been inactive for a year or less. You can search the database by the entity's name or owner's name. These are records/information of businesses that are registered with this department, other permits or licensing are not part of the search results.
Depends on whether you are planning on turning in fingerprints. Otherwise, you will get a name based search, which can include people which share the same name. Certain employers ask for a fingerprint based search as a pre-hire requirement.
In probate, wills are generally part of the court record and available to the public, similar to other court files, except, you may need to request it from a separate probate clerk. While the person is still alive, wills are not public record, they are considered private. Each jurisdiction has their own process which can differ from one to another. The North Dakota Supreme court offers a public webpage which summarizes ND's probate process and familiarity with the administration of an estate.