Don't be affraid to use scatter, scatter is safe and secure. All the transactions are signed locally, on your computer, before going on the internet. Your EOS Private key never goes on the internet.

To manage you Keys permission, I would recomand you to use Scatter + MyEosKit.

If you are not sure, you can create a small acount, with only a few eos, only for training the key permissions. Once you are sure how it works, do the same at your main account.

Have a nice day,

Thierry