I have experience in this area with federal probation.
-They can now differentiate between exo and endo test. Long ester test is probably detectable for around 2 months.
-Of course they will test for all anabolic steroids, not just test.
-The bold hanging around in his system could get him violated, depends on the PO.
-You don't have the same rights on probation as a normal citizen, they can fuck you. It's all about the PO and the judge.
-They WILL raid his house at some point during the probation period, everything will be searched, anything suspect will be seized.
-Remember the PO has one goal: to violate you and put you in jail. They have a very high workload, and the only way they can reduce their workload is to violate people (ie jail).