Can an employer give you time off of work for failure of a drug test and return you to work with out a follow-up test?

Failing the drug test could be a legitimate basis to deny you a discretionary bonus, but it depends on the policy with respect to how bonuses are...

What rights do I have to keep my original position that I was hired for

Your rights are very fact specific here. More information is needed to know if they can do this. You should contact a local employment attorney...

There is no harm in applying. Just be honest about the situation and they will let you know if you are eligible.

This I feel is discrimination and why they do that?

It is unclear what you are seeking advice on here.

Do I need to bring proof of employment in to court ?

Bringing some form of proof would be wise.

Can I sue for lost wages because of a failure to pay and come up with a contract for me even though I was working the whole time

You are entitled to pay for the work you performed. You can contact the Department of Labor or a private attorney to file a claim on your behalf.

Can drug test results be shared with new employers

I don't know why the results would be shared with subsequent employers. That seems unlikely to me.

I don't think you have a right or expectation of privacy in the content of your interview. That said, if someone is spreading false information...

Should I have been notified when this neglect happened? How would I find this information out?

What type of licensure do you have? That would help in assessing whether you have any right to notice.

It is unclear what your question is.