I will give my opinion on scale 1-10, 10 being most liked.
Elodie Mabel- 9 Elodie is very pretty and Mabel has a sweet vintage vibe
Mila Amelina- 2 but Mila would get a much higher score paired with a different middle name
Esme Melusine- 8 for esme but not sure about the pronunciation of the middle name
Megan Abrielle- 5 its kinda meh for my taste and compared to the other names you like but not bad
and Elin Mariel.- 6
If I may suggest...Lousia seems like it might be your style :)
From your list, I like Esme and Mila (Love, love, love), but with different middle names. Melusine (maybe I'm mispronouncing it) reminds me of muesli. Mila and Amelina don't go together, as both end in a (rhymy), and they will slur to become Milamelina.
Suggestions: Jessamine, Mina, Milena, Marin, Mara, Savina, Emiliana, Cecilia, Cressida, Delphine, etc.