Learn English – Difference between “by this way” and “in this way”

Yes, there is a difference. One usually doesn't have a meeting "over" something, without using more words. For instance,

"All the employees at SEI Corporation are invited to the meeting where we will go over the new internal communications system that the company is about to bring in."

You are correct, however, that "over" can also mean "about something," as in this example:

We argued over who would do the dishes.

So why wouldn't we say, "We had a meeting over who would do the dishes"? It is largely idiomatic, but to a native English speaker it would sound odd.

A better choice than either "on" or "over" in the original example would be "about," except that it is used later in the same sentence. The sentence could be rephrased to use "about" like this (changing the second instance to "going"):

"All the employees at SEI Corporation are invited to the meeting about the new internal communications system that the company is going to bring in."

I feel like amazing at/in will (more or less) follow the same pattern as good at/in. This is likely because the two words reflect something positive about the subject.

In and at are sometimes interchangeable. In this case, I would use at:

1. She is good at painting. → She is amazing at painting*.

According to this post, good at is generally used with activities. It provides other examples:

2. He’s good at football.
3. She’s good at product design.
4. Her mother is good at Trivial Pursuit.
5. When Fatima was only six, she was good at drawing.

In each case, you can swap good with amazing and each case remains idiomatic.

The post also makes a note about academics. It says

When it comes to school subjects, both “good at” and “good in” are used.

For example,

6. Max is good at math.
7. Max is good in math.

Of course, these are general guidelines. There are exceptions.

8. She's good in bed

This means she's good at sex. You cannot replace in with at in 8 because bed is not an activity.

This can sometimes be extended to other places where activities are done (as this post points out), for example

9. He's good in the kitchen. (He's good at cooking; He cooks well.)

You can swap good with amazing in the previous examples and they should sound fine. Other positive descriptions, like skillful, should work too. Again, this is a rough guideline and there probably more exceptions.

_{*You can rewrite this as "She is an amazing painter." I prefer this over the original, although the original is ok.}