Subscribed / Local / All could just be a button-set on one line, and the headings really don’t need to be as big as they are.
Lemmy will not prevent you from having to read the rules of your community, nor your instance.
For best results, in any online community, it is wise to read the rules before you contribute.
Can’t say I ever experienced that in the 11 years I had my reddit account. Perhaps you and I post differently?