I blieve it is a misconception that inside players shoot more free throws in basketball. The majority of guys who get to the line a lot are guys who drive to the basket. That's the way it has been in every level of basketball I have played or seen. There are certain dominant big men who teams foul because of the No-Better-Choice factor, but the majority of players with high free throw attempts are SG / SF types with great driving skills. At least as many as big men.
I noticed you mention that inside guys shoot more FT on the nomenclature page of the rules, and lately I have seen managers cite this as a deciding factor in tactic choice. I think driving skil should be considered more in whether a guy gets fouled while shooting or not..
Once I scored a basket that still makes me laugh.