"Jag vill ha en sekreterare."

I don't know...I think "I want a secretary" is perfectly fine to say in the business world or in general company, as long as you don't say it with any sort of inappropriate innuendo. If you're just saying to your boss or co-workers, or friends or family or whomever, that you want a secretary (because presumably, you're overworked, or maybe just lazy), I don't think anybody would react negatively.

Just remember that 'I would like to have a secretary' is Jag skulle vilja ha en sekreterare in Swedish. vill ha vs skulle vilja ha correspond very well to the English want vs would like.

I'd be more likely to say "I need a secretary," regardless of the circumstances.

I disagree comepletely. It doesnt have that meaning at all unless you specifically say it in a way that implies it. Its perfectly fine to say.

I think the difference is whether you are talking about a specific person or not.

If you say I am a secretary, you don't use the 'en' because you are talking about a specific person (me). Here, the word secretary is describing "my job title".

If you say I want a secretary, you are not talking about a specific person. Here, the word secretary is describing "a person who does that type of job".

Not sure if I've explained that well, but hope it makes sense.

I'd suggest 'en' may mean he'll be satisfied with having only one secretary this time ;)

When what you want is a noun. Read more here: https://www.duolingo.com/comment/5892480

Directly translates that would be "Jag skulle vilja ha en sekreterare". "Vill" - "want", present tense. "Skulle vilja" - "would like", present subjunctive.

Yes, in the indefinite they are the same.

ha is the infinitive form "to have". har is the present form.