Denise is a great character who is sadly underused.
I would like her to get together with Masood, I think they would be a lovely couple and they could raise Kamil and JJ together.
Yes, she was very wrong to hit Patrick. She was drinking and in a very bad place at the time. Normally she is a lovely person, I think. Far nicer than the dreadful Kim. I love Denise's relationship with Patrick, too. They have gotten through the rough times and love each other a lot.
As for the Lucy fight, there were two of them in it. Lucy gave as good as she got. But of course Denise should have told the police about it. I can only assume that she knew it would look bad and she also did not want to add to Ian's misery but it was cowardly not to do it. Understandable, but cowardly.