@Scarby9
Obviously I don't know what the process is for the job area for which you applied.
However, we would only raise at interview something from your application if it was a concern, unclear or raised questions.
We ask all candidates the same 7 core questions which give the opportunity for them to use examples and draw on previous experiences which they may also have included in their application, as well as anything else they feel is relevant. We want to see how you can use your prior experience in our field and that particular job. We score on relevance of answers, quality of links with previous experience etc.
So yes, for us it is up to you to include what you want to tell us in your answers.
We do give feedback to everyone we interview, whether successful or not.
In future, when someone says they will let you know, I would ask when you will hear.
We have the same procedure for the first interview - second interview is more personalised, so someone might ask you about your application then but not necessarily.
Two days to get a reply - it might be that the decision makers are busy with other things. We give written feedback on interviews - to both successful and unsuccessful applicants and that's the part that takes the time - our requirement are complex, that balance between saying something encouraging and useful - and saying something upsetting and pointless - we get one person to check this (he has a particular skill in this area) and that one person is always very busy - that's what causes the delay for us.