Thanks for the query.
1. Answer: I understand. You want it in a single process but no, it’s not possible. You need to create an invoice first before receiving/recording a payment. Two need to be added separately.
2. Answer: No, it should come. Just make sure you have added that vendor for this product that you want to purchase. Like; if Product-A is made for the vendor-X, So, when you create a purchase, if you select vendor-x, then only you’ll find the product-A. If you select vendor-Y, you’ll not get Product-A, because it’s a product of vendor-X.
3. Answer: Did not get this well. Adding Employee in HR adds them in the Accounting users as well. No need to add them again.
4. Answer: We’ll have a frontend soon. So, you’ll be able to use the whole accounting system from a separate and beautiful screen.