I agree that there are no hard & fast rules. One of the tests of CA3 is being able to judge whether the recipient/audience will understand particular language/terminology. If in doubt, as bystander says, you should explain the concept and then associate that with the terminology being used (i.e. define it).
In CA3 it is generally best to err on the side of caution. For example, one of the trustees may be a new member trustee with limited experience of the operation of pension schemes. You should form your communication so it will be understood by that least-knowledgeable member of the audience, whilst not coming across as condescending to the remainder of the audience.
Of course, for all CA3 questions you can assume that the recipient/audience has "some business knowledge", as this is stated in the CA3 syllabus. However, you do still need to consider each situation separately - looking at the particular situation described in the question concerned. No hard & fast rules!
So personally, I think that "asset" will be understood by any individual with "some business knowledge". "Liability" will be understood perhaps at a very general level, but not necessarily what that means for a pension scheme - i.e. the specific liabilities of such a scheme. "Funding level" and "scheme deficit" I would be much more cautious with (would you have understood these before studying to be an actuary?!) and aim to either avoid or to explain before being used.