You have a very good chance at getting unsupervised time with your child, as long as you are abiding by your probation conditions and can show you are drug free. You should file a paternity action ASAP.
This is a third degree felony punishable by up to five years in prison. I agree with the previous answer that a prison sentence is highly unlikely, but you need an experienced local criminal defense attorney to make sure your case is handled correctly. It's also a good idea to refrain from talking about the facts of your case any further, except with your attorney.
I agree with my colleagues. If he continues to be unreasonable, file a Motion with the Court. Parents are supposed to be flexible when it comes to parenting time. The judge would not be happy with him, and may even order him to pay your attorney fees. Contact a local family law attorney for a consultation.
This question is tough to answer with any degree of certainty. It depends on a lot of factors, such as the facts of the case and the judge you are in front of. The maximum sentence is 5 years in prison.
Sentencing in Florida is based on a scoresheet, and your brother-in-law will receive points on his scoresheet for his priors. The more serious the priors, the higher points they carry. So, yes, the Michigan priors, and priors from any state, will affect his sentence.