The betrayal of the Covenant (Dark Souls)

Took a discount on the Remastered version, and now pass. Previously I played pirates on the original and passed on litsuhe the second and third part.The real question is this: what qualifies for treason and how to avoid it? Is it possible to have the maximum rank in every Covenant? My thoughts on this matter (correct if wrong):
Not to betray the Covenant you can't kill the respective NPCs, and leave the Covenant need only Oswald from Karim (before joining the new). Thus it is possible to join all covenants, then quit the one Covenant using Oswald and join the other already at the fire. All right?