The paragraph under consideration has nothing to do with his moral integrity.
The context is about how to understand a specific paragraph in an article about a rich man.
Can I use “the paragraph in discussion" or "under discussion” to replace “under consideration”?
Can I say "something in discussion" to refer to the thing being discussed?
Assuming the consideration in question is a discussion, yes you can use "under discussion" as a replacement.
You might consider the paragraph in question or the paragraph under examination or many other similar variations.
Yes, you can.
You can also use the idiom "in question".
Eg. Besides the person in question, there were many other witnesses to the incident.
