With future perfect (F2) you jump to a point in the future, turn round and say some action is finished then. Actually a complicated thing and cumbersome and in most cases you can express the same idea much simpler without using F2. This tense existed in Latin and it was imitated by writers.
In current English usage, muse can refer in general to a person who inspires an artist, writer, or musician.
You can be a muse without having a perfectly-proportioned body and a pretty face. Whatever it is that makes you different, play it up. An artistâs quest is to create something the world has never seen, something truly original. An artistâs muse is not just a model or mannequin, but a source of original energy and life. For example, Pablo Picasso's series of muses, including Dora Maar and Marie-Therese Walter, helped him see the human body in a new way and inspired him to share his insights with the world.