Would you hire someone with dreadlocks?

Sure.Judging him only becouse he has dreadlocks is stupid..

I would not have a problem with it if they are qualified.

We had a colleague who had dreadlocks and I swear on some days when he walks into the office it looks like he just walked from a homeless shelter but he was one of our best employee.

He is now in a management role and doing fairly well.

Is he black ?

Yes. I can't think of a job affected by hairstyle really.

Nope

Depends on if the position is a client/customer facing position. There's a reason IT people usually look sketchy, it doesn't matter what they look like since no one ever sees them. If it's a position where looking professional is an issue, offer them the job with the stipulation that they'll have to conform to certain standards of dress - this may mean getting rid of the dreads or styling them in a way that's acceptable for your company.

They look unprofessional

If it's a white person with dreads, no.

Of course, it's just a hairstyle. If they were a good candidate in every other way, I wouldn't think twice about it.

I guess it depends on the person.
If he seems worthy of the job, then sure

It would depend on how well he maintains his locks and whether or not he's a clean person.

Never.