Unable to delete users since CB and plugins upgraded

I have been trying to resolve the problems for more than 2 weeks.
I have even had a friend who is a IT University tutor try to solve the problems.

Please don't sit in frustration for so long. Just come here and ask. We're here to help you.

Whenever someone comments on, or gives a comment or activity a like, the whole activity is posted to the stream, leaving the original comment in the stream as well.

That's exactly what it's supposed to do. Facebook does the exact same thing, but you don't notice it because streams are more active there. I've added a feature ticket to review suppressing the original post if and only if it's on the same page as the reaction post.

forge.joomlapolis.com/issues/9344

This makes the activity stream very repetitive, and in the case of an image or gallery of images, the whole stream is the same images reposted dozens of times for each like or comment.

That happens with relatively inactive streams as there's no other activity filling it out.

If earlier post was liked or commented on, it was moved to the top, not copied to the top.

That's Comment Bumping. That still exists. Enable that if you prefer it over it generating commented on activity. There was no Like Bumping, but I can look into adding that.

forge.joomlapolis.com/issues/9343

We have turned off all the streams except Profile activity and Module 137, but the stream is still showing the same multiple copies of an activity for each like and each comment.

It should be merging those. So for example if 3 people comment on a post it shouldn't show 3 activity entries. It should show the original, if it's within the current page, and the commented on activity. Is it showing 3 for example for you? If so that's a bug with the grouping behavior.

OK.
Thanks for the clarification.
We are going to turn the stream off.
We only have a small community of 1000 people, so the activity stream is not very busy, and due to the way it works now it is driving people away from interacting.
If someone posts a new gallery and 20 people comment on the gallery, the whole page is just 20 repeats of the gallery.
If they are using a mobile device they have to spend a long time scrolling down to find a different topic/gallery/event.
This has caused most of our users to stop using our "Site Activity" page, which in the past was the most used page.

Using the comment bump does not work very well.
Only the new comment is bumped, not the whole conversation, so there is no context for the comment.

You say that this is the way Facebook works, but I have been in to look at Facebook.
Our town posted an article 2 hours ago.
It has had over 200 comments added.
I have been back to more than 2 hours ago, the article only appears once in my stream.
It moves to the top of my stream each time a new comment is added, I do not have 200 entries of the article in my stream.
  
I looked at other posts, I have no duplicate articles in my Facebook stream, no matter how many times people have commented or liked an article.
I have followed a thread that has been running several days, it is not repeated once in the stream.

I have attached an image from my Facebook stream.
Despite having over 600 comments, it only appears in my stream once. 
 

If someone posts a new gallery and 20 people comment on the gallery, the whole page is just 20 repeats of the gallery.

That's certainly not how it should be working. There's a Dynamic Grouping feature that should merge all similar posts within the past 10 days together.

Using the comment bump does not work very well.
Only the new comment is bumped, not the whole conversation, so there is no context for the comment.

That again is not how it should be working. Comment Bumping as enabled in CB Activity > Parameters > Activity should bump an activity to the top of the stream when a comment is made. It shouldn't be bumping the comment itself.

Will look into both as am unsure why this behavior isn't working for you.

This is how the comments are appearing when they are bumped. 

Looks like you have both comment activity and comment bumping enabled. You ideally should only be using 1 or the other. As is you're creating a new activity for the comment and then bumping the activity post to the top. So yeah that will look a bit goofy.

It does look like the grouping is working though. That's why it says There's 15 others, etc.. That's the dynamic grouping behavior. If it's showing posts outside of that group then those posts are likely outside of the 10 day window. You can however extend that. Within CB Activity > Parameters > Streams in the Grouping section adjust the Days parameter to whatever you like and it will continue to group for further and further out posts.

I am working on a way to suppress the original post when there's reaction activity like that though since that isn't implemented.

So what exactly are you wanting it to display in that scenario. You've a like activity for a post and a like activity for a comment on the post. Are you wanting it to only show the like activity on the post and not the comment? Below is an example of what the dynamic grouping should be doing.

 

This would be comment activity on activity and comment activity on a gallery upload. Note in this example the bottom post has no comments as I'm just creating the entries manually for testing purposes.