A: Those of us who practice exclusively Iowa law don't necessarily know how to navigate PACER (the federal filing system) let alone how to request the appointment of federal counsel.
Your friend could call the federal public defender's office and see if someone over there knows.
Here is a brochure I found on the Iowa Federal Public Defender's page: https://app.box.com/s/h2ycs85tj1mukbhpg0hmdqcmvucp4tsv
A: In Iowa, where this question appears to have been asked, the judge generally retains the latitude to accept a plea while rejecting a plea offer and imposing any legal sentence. Yes, that would include changing unsupervised probation to supervised probation. If you have questions about this, you should discuss it with your attorney.
If you filed a written plea, you may find that a phrase like "the Court is not bound by the plea agreement and may give me the maximum sentence allowed by law, including any enhanced sentence" is written right into the document that you presumably reviewed and signed.
You cannot request a new judge in Iowa because you don't like that the judge rejected your plea or imposed a sentence you didn't like.
A: It is possible (but unlikely) that an attorney will offer pro bono representation in the sort of case you're describing. You are always free to call around and ask, but bear in mind that you are essentially asking someone to pay to work for you. Time that lawyers spend working pro bono is time that they spend accumulating expenses that aren't being paid for by a client. Gotta pay the internet bill and the Westlaw bill (etc.) whether or not the client pays for the time the lawyer spends using those services.
The defendant in the case you're describing can apply for an attorney at public expense if he can't afford to hire a lawyer. Here is a link to a financial affidavit he can fill out and submit to the court in support of his request:
If the defendant is indigent, the Court will appoint the public defender's office to represent him. If the public defender's office has a conflict or is too busy, he may instead be appointed either a lawyer with the juvenile public defender's office or a private attorney who contracts with the State Public Defender's Office.