As there is no response we close the ticket.

As there are no more upvotes we decided to not consider this functionality. So I close the ticket.

We don't plan to create model directly from db connection. 

Creating model from SQL scripts is already possible.

As we has introduced copy/paste of group of columns and there are no more upvotes we decided to not consider this functionality. I close the ticket.

Grid functionality has been alredy introduced. You can find this feature in Format tab of Model properties (right panel) as shown on the following screenshot.