Order Import Cs-Cart 4.11

We are using Cs-Cart 4.11.4 Multivendor. I want to import orders from another e-store by xml or CSV.
I see that to import orders there is a two level job: 1-Orders import 2-Order Items import.
I tried some CSV files to make some trials for importing to see if its working. We are having some issues;
- For Orders Import: Whatever Order Id comes with the new imported order Cs-Cart continues after that number. For example if last order ID At Cs-cart is 100 and if I import a new order with ID 10000, now the last two orders's Ids at Cs-Cart is 100 and 10000 (100 from Cs-Cart own sales and 10000 from the import). After this, if a new order comes to Cs-cart it numbers it as 10001, continuing the last number which is from the imported order. We would like it to continue from its own number which should be 101 instead of 10001.
- For Order Items Import: There is a column called "Item ID" I learned that it is for different options of products, but I give some random number to it and it looks like working. As the CSV file is coming from another source from another e-store which is not cs cart I am not sure how to assign a number to "Item ID" or just giving a random number is ok? I tried to leave it blank but then import skipped it and did not import that order.
- Lastly, After I import Orders and Order Items Cs-Cart doesn't track product inventory.
I hope I explained my problem neatly.
Do you have any information to solve it? Can you assist me through this process of importing orders by CSV or XML to Cs-Cart?

1. It is not possible since auto-increment value is used for order ID in the database. It can cause issues in the future

2. Item ID is generated by the special function. It takes into account product ID, selected options and other additional parameters. If your solutions works, use it.

3. What do you mean?