This section of the standard is pretty much copied from the BRC food standard, and there are mountains of resources out there for that - you can use pretty much all of them as the standards are so similar in this area (I run the same system across our Food and A&B certification/activities).
As a starting point, the attached guide from BRC is worth a read.
The below are also some examples of thread from IFSQN, each of which contains various useful links, and there are many more - the search box towards the top right of the page will bring up loads of information.
In terms of your specific questions:
4.8.1 - the threads above have some links. Trello, RASFF etc are popular free resources. If you're a member of an industry body then try also contacting them as they may monitor things of particular reference to your industry.
4.8.2 - you'll need to do a vulnerability assessment. Have a read of the BRC guide that I've attached. The feasibility, nature, and relevance of testing will very much depend on the types of products that you handle. e.g. probably not that relevant for whole fresh fruit. If you can provide detail on the product range in question then we may be able to make more specific suggestions, but again it's possibly also worth talking to an industry body in your sector as they'll likely have lots of detail on this.
4.8.3 - yes, this can include preventative controls and documents, but they'll obviously need to be relevant within the context of the product, type of risk, and level of risk. The interpretation guide actually specifically states that it is preferable to use proactive controls rather than reactive measures such as testing. (If you've not yet got a copy, it's worth getting the interpretation guide - available free if you're on Participate, but worth buying if not).