"He didn't return back yet" sounds like he might have been moved for a court date, a trial or testimony.

Yes - you are entitled to whatever balance you had in your account, barring you owing any fees or restitution upon your release.

Inmate in federal custody are released in the early morning - weekdays only. There are normally arrangements made in advance before the date of release. If the inmate has halfway house or supervised release, there is a component to that as well. The BOP usually arranges for a bus ticket and a ride from the "town driver" from the facility to the depot.

There are too many variables in the information provided to give you an reliable answer. Usually, the release statement is what you can rely on and if he has to be in a treatment center, then that is where the bus ticket will take him. In residential treatment, they often times will allow a portion of the time on home confinement but again, there is no way to give you an answer that we would be comfortable telling you is