3) Confirmation email for user from SAP about the delivery time. We discussed if it's possible to implement. And does it make sense if we also need to add then time that carrier company will need to deliver the order? Or how it works in other markets for example?
Other shops are using the local catalog delivery time (MVGR2) that we are getting from SAP. This is the average time in workdays that it takes for the goods to arrive at the customer.
With a country as big as Russia this may not be a very reliable time. So you may not want to use this in the Shop.
For a better quality of delivery times we have the so called V-LOG delivery time calculation, which can do post code dependent dates. But this needs setting up with V-LOG. And that will take some time and is not part of the V-RUS shop set up.
Alternatively - if you get a good delivery date in SAP after the order has been processed - you could consider sending an email order confirmation from SAP with the delivery date. But again - that requires set up time in SAP.