3.
In the final fight between Chuck Norris and David Carradine, doubles were supposed to be used. But when the scene began to shoot the actors refused their services. The producers were against it, fearing that one of the actors might get hurt, because it was assumed that full contact would be used at some points for greater effect. But Norris and Carradine insisted, and in the end, the director of the film, Steve Carver, also took their side. After that, the producers gave up on everything..
4.
The film was originally rated R by the MPAA. However, the creators of the picture filed an appeal, which was granted and Lone Wolf was released with a PG rating (at that time the equivalent of the current PG-13, with which almost all comics are now released, or the same Bond). This is quite surprising, because the word fuck is used several times in the film and there are some pretty bloody moments associated with shooting.