1. OH&S opportunities and other opportunities are best described in ISO 45001 clause 184.108.40.206. OH&S opportunities are described as specific OH&S activities that would enhance the OH&S performance, with examples such as adapting work, or eliminating hazards and risks. Other opportunities would consist of other activities that would improve the OH&S management system that are not seen directly as OH&S opportunities. The wording appears to be this way to ensure that people include all opportunities to improve OH&S performance regardless of how they classify those opportunities.
2. So, other opportunities are things you can do to improve the OH&S performance that you might not directly think of as OH&S opportunities, including opportunities from other management systems that have an affect on the OH&S performance. An example might be if you were replacing a chemical in your process in order to improve the quality o f the product created. The new chemical will have different OH&S effects than the old chemical and the OH&S risk posed by a new chemical may become part of your decision of which replacement chemical to choose.
Opportunities are not necessarily related to the risks. OH&S opportunities are about reducing or eliminating the risks associated with hazards, so for these you can think of how to make the risk less as an OH&S opportunity, but other opportunities are not necessarily from risks. These are top level opportunities that you might identify as part of a SWOT analysis or other strategic planning process to identify uncertainties you can capitalize on.