If I Become an Editor, Can I Write Content As Well?

Yes! You can become an editor, and continue being a writer without problems.
You just cannot edit your own work.

Editors generally prep AND edit, but it's also possible for you to  
prep and write the same article. But editing your own writing is not  
allowed.

Editors and writers are 2 independent jobs.
If for some reason one of your accounts get banned / paused, it will not affect your other account.