Haven't we been over this?
Yes, confessing will make things worse for the reasons we have covered at length.
Is there anything new that you wanted to know?
As I've already said there is no sense in confessing unless the evidence is overwhelming and you are being offered a good reason to confess.
Yes, it would.
That is fraud.
But you have done it now so there is no point in going over that.
Just do nothing and wait to see if they can prove this or are even interested in it.
1 Yes, it would for the reasons we have covered.
2 Yes, the police would be interested in a report.
there is no defence in the fact that you have now paid.
No, you should make no admissions to either of them.
A caution is not an option realistically.