In my opinion you are not right. I am assured. Let's discuss it.
You are not right. I can defend the position. Write to me in PM, we will communicate.
Yes, really. I join told all above. We can communicate on this theme. Here or in PM.
It seems excellent idea to me is
At you a migraine today?
Прошу прощения, что я вмешиваюсь, но, по-моему, эта тема уже не актуальна.
I consider, that you are not right. I am assured. I can defend the position. Write to me in PM, we will talk.
I can not take part now in discussion - it is very occupied. Very soon I will necessarily express the opinion.
seems brilliant idea to me is
Имена участников (разделяйте запятой).