Export not matching data on screen

Hi,

From your screenshot it seems that you're using the Orders>Reports menu to export that data from a report.
(it would be great to specify clearly what you do when you report a problem)
Also, in such case, it's a good idea to provide a screenshot of the settings of the report, so that we can reproduce the issue without having to try different things.
Luckily, I was able to reproduce the problem and made a patch for it. You can download again the install package of HikaShop on our website and install it on yours to get the patch.

Regarding your second point that's not possible because it's not logical. This report is an aggregate of the sales of the products. You have one row per product (or variant), even if the product is bought by 10 different people in different orders. Then, even without that logic issue, adding an extra column there is not easy as you'll have to modify the core file of HikaShop generating these reports to load the corresponding data and it will be problematic since the query which loads the data only loads one element for all the orders of a product and so it's not a simple modification.
If you want an export of your orders, you're not using the correct tool. Instead, you want an export of the order data with a mass action via the menu System>Mass actions. There, you'll get one row per order and some you can easily get the comment of each order. The drawback is that you would have to calculate the sum of the quantities of the products. Unless you use actually both CSV exports one next to the other.