Neither of your proposed options sound correct. Neither and nor are often used together, for example:
He ate neither meat nor bread for supper.
The meaning of which is
He did not eat meat for supper, and he also did not eat bread for supper.
Now, in the above examples, the neither/nor construction is idiomatic because you're referring to two things which he did not eat for supper. That is
He ate [x] for supper.
He ate [vegetables] for supper.
He ate [neither meat nor bread] for supper.
As you can see, both of the items referred to by neither and nor are things which were not eaten for supper. So it makes logical sense to pair them this way. (I'm not saying this is the only way in which neither/nor can be used, but it's common, and hopefully will help you understand the problem with your sentence.)
So now we return to your examples:
I am not your slave, nor do I have to follow your advice.
I am not your slave, neither do I have to follow your advice.
Neither of these sound right, and here's why: not being a slave and not having to follow someone's advice are two completely separate ideas. If they were both things I am not (your slave), things I don't have to do (follow your advice), or, as mentioned previously, things I didn't have for supper, then you could combine them with neither/nor. For example:
I am neither your slave nor your pet.
The category is things I am not; I am not your slave and I am not your pet. This is fine.
Now, it is also possible to change I do not have to follow your advice (things I do not have to do) into I am not required to follow your advice (which now makes it a thing I am not). In that case you could use neither/nor:
I am neither your slave nor required to follow your advice.
Now the construction makes sense because both items fall into the same category. This is actually a useable sentence for your purposes; you could say it and you would be understood just fine. It does come across as a bit formal, though, and I don't think you're likely to hear it in casual conversation.
So to select the wording which is most likely to be useful in conversation, forego neither/nor entirely since your two items are not of the same type. Instead say this:
I am not your slave and I don't have to follow your advice.
The and combines two separate but true statements. Simple and to the point!
So my original answer was incorrect. "Hope this helps!" is a declarative, not an imperative. Instead of deleting my answer, I think it might be helpful to explain why I should have known it wasn't an imperative, and pull out the bits from the original that were correct.
Imperative clauses are usually in the second person, like:
"Hope for the best!" (You should hope for the best.)
A declarative clause is just a statement, like:
"I am editing my answer." or,
"Hope this helps!"
The second person and first person form of hope are the same, so I got a little confused because I didn't think about it carefully. I should have been able to tell that the clause wasn't an imperative because an imperative is usually a command directed at another person, and "Hope this helps!" is stating something in the first person.
I would expand "Hope this helps!" this way:
I hope this (answer) helps you.
You would say "This answer helps me." and not "This answer help me." because the subject of "help" is third person singular. So, "Hope this helps (you)!" is OK, but "Hope this help (you)!" has a verb agreement problem.
In your suggested sentence, which is grammatical, you changed the wish from the present (helps) to the future (will help). This is OK, but it's not exactly what the original author expressed.
Best Answer
It's elliptical, that is, it drops some words for economy of expression, since the words omitted will be obvious to the native speaker.
American Heritage Dictionary "ellipsis"
"1. a. The omission of a word or phrase necessary for a complete syntactical construction but not necessary for understanding.
b. An example of such omission."