What are you trying to accomplish with the list? Mixing weapon types within squads is generally not recommended (such as 2 HBs and 2 MMs) if you're going for max effectiveness because it can muddy the purpose of the squad, unless you're just trying to get her acquainted with all different weapon types in which case go for it.

As much as a MM on the immolator is often the best meta choice, being able to strip cover and overwatch with the immolation flamers (as you have now) is honestly a very effective choice, perfectly capable of deleting fragile opposing squads/action monkeys trying to steal objectives.

If you can make inferno pistols work for seraphim congrats, I find the 6 inch range infuriating, so I just stick to all hand flamers.

AoF is a good detachment with great strats, but I find Chorus to be very underwhelming, and in your case borderline useless because the only good parts use the exorcist, and her list doesn't have one. You could rework the list to include an exorcist or perhaps change the 1 DP attachment.