The only way to import would be to export a private key from your main wallet and store it somewhere safe
This sounds like backing up rather than importing
No, backing up would be saving the .dat file of an offline wallet. A private key is a few strings of code/characters, with it you could easily
sweep your funds form old wallet into a new wallet. Which is a way of importing. Not backup.
Not really sure on why you're talking about an offline wallet here

. I said it was "more like backing up rather than importing" because importing means adding/associating your private key/s into a wallet that supports it but you stated "...and store it somewhere safe" which is kinda vague since it can also be in other places which is not a wallet..
Another thing, There is a difference between sweeping and importing. Importing as I mentioned above is merely adding your private keys to a wallet while sweeping is sending your funds to your chosen address through an on-transaction and the private key that you swept won't be added to your wallet (where you sent the funds to).
So now I`ll probably have to wait another 2 weeks to get another useless response from them
You should probably consider importing and switching to a new wallet