Can you be turned down for a job if a relative currently is employed there?

Whatever you read on "www.gov" regarding family members would apply only to government jobs.

It would be perfectly normal to reject family members, especially if they'd be working in the same department, etc.

Whatever they've done with somebody else's wife is irrelevant. And they probably have it structured so she's not in the same department, or with the same supervisor, etc.

You cannot challenge the decision if they don't want to hire you.

They can "not hire" someone for any reason or no reason.

Yes

Yes, you can be turned down. Chances are good a family member has mentioned that you wouldn't be right for the job.

No. I'm suing the hospital my dad works at for refusing to hire me as a neurologist. I meet none of the qualifications, but i feel entitled. It should be about who you know - not what you know.

Unless it is a government job the requirements listed on the government website do not apply. The employer is free to make their own rules about what they consider family. They can reject you for employment because your nephew works there.

Yes

yes. It would depend on the job and reporting structure of the company.

Sorry but EVEN if they set a precedent by hiring the boss' wife, it has no bearing on what policy they choose to go by when hiring new employees. I once worked at a YMCA office; two other employees (another office worker and a Phys Ed instructor) got married and both were asked to decide which would choose to leave voluntary or they'd decide. The young lady got an attorney who spoke to the Head of the YMCA and told him they were each hired before marriage and they could NOT, therefore, fire one or the other or both based on their "rules." They both remained on the job. But most employees refuse to hire relatives as policy. You can try to rebuke their policies based on the precedent but they'll turn around and simply say, "We don't need you or your skills. Then what? They can say they don't like the way you expressed yourself during the interview and they will not say why nor are they required to do so (explaining why would leave them open to more questions which they'd rather not deal with in a court of law should you try to sue). Seems unfair but it is what it is. Sorry. The reason why employers don't like to hire relatives (and in some cases, friends of employees) is that there is potential for conflicts to arise from "cliques" or cronyism that can and often do get formed, like in decision-making matters, or in interactions with other employees, .

yes. It would depend on the job and reporting structure of the company.

There is nothing you can do about it.
Unless they discriminate against you based on a protected class (age, gender, orientation, race, religion, etc) then there is no grounds for complaint.

depends upon the policy of the employer. It is not unheard of.