Double sharps after MIDI import

Hi

I'm quite new to musesocer (which I love already). And I'm quite a lay regarding music theory. So I hope I do not overtax your patience with me ...

When I import the attached midi file, I get many double sharps. Can I prevent this somehow?

Also, is there a way to tell musescore to Import the file in the correct key? I know that the Information, that it is in C-Major is given in the midi-file (as I can see in the midi-Sequenzer).

Correcting to the correct key seems easy. Correcting the double sharps seems cumbersome. Perhaps there is a way I just not found yet?

Thanks for your help
Ernst