Hi,

so blockchain.info did switch to this new interface, right? I know it has been implented permanentely without the option to switch to legacy, like a few month ago. Back then I did download the Backup (which is a file named "wallet.aes.json"), after that I still received and spent a few BTCs.

So, does that file contain the private key (which I believe is necessary to import the BTC address to another wallet)? If yes, how do I exactly import my blockchain wallet to another wallet? And if I manage to import it, do I have the exact same amount I have currently on blockchain.info, as I said I did receive and spent a few BTCs after I made the backup in the old interface.
And can I recommend a desktop wallet which offers a two factor authentication (e.g. SMS code that is sent to your mobile device).
I am pretty much a noob when it comes to technical stuff so be aware while giving me instructions