Regardless of the legal can or cannot's of the licensing I think people need to look at consider that using software without paying for it will discourage developers from producing new software for RISC OS. We can't let that happen.
The market for RISC OS is small and doesn't have the same economies of scale that larger markets have. Developers charge what they think is fair to make a return on the investment of time they make to create these products.
Anyone who can develop a good quality application for RISC OS could almost certainly earn a lot more developing on other platforms and so many of them do this for love of the platform not to become the next Bill Gates.
Please consider these things before breaking the licensing conditions of a RISC OS application.