Yep, that’s correct. The key thing is that your statement on QuickFile matches your actual bank statement (value wise). The descriptions don’t necessarily need to match.
It won’t automatically tag (if you have 2 sales invoices for £10 for example and you have a payment for £10, we have no way of knowing which invoice it relates to). But you can then tag it from the bank statement rather than the invoice (click the Tag Me! button, select Payment from Customer or Payment to Supplier, and select the invoice, or take the action as required).
It can be tricky to get right, but it’s optional. Again, it comes down to how you prefer to work. I know some users swear by the tagging rules, but other users won’t touch them
As above, the feed won’t tag the transaction, so this would still need to be done manually. By when you tag the invoice (see the answer to point 2), you will see an option to send a notification email which would be the same as if you used the “Log Payment” option. The topic I linked to above shows some screenshots of this for you to get an idea of how it works.
There are two options here then. If you use the tagging option from the bank statement screen (that is, using the data from the bank feed for example), then you can link to an existing invoice, or create a new one. With purchases the data on the account doesn’t have to be accurate and matching their invoice exactly - as long as the date, value and nominal code is correct, this should be enough for HMRC. Of course, you would keep a record of the actual invoice just in case it was ever queried (whether this be on paper, email or tagged and stored within QuickFile).
The other option would be to leave the transaction as untagged, create the invoice as you normally would, and then go back to tagging it.
The truth is - QuickFile offers various ways to work and everyone has their own “little way” of doing things (similar to saving a document for example - do you go to File > Save, Press the save icon or even press Ctrl + S?). As long as your data is accurate, everything should be good
[Edit]
Just to add to the bank tagging process above - there’s a guide, including screenshots, here: