What change do you want to see on your main class for Endwalker ?

[CKNovel]

To be honest, I'm not a big fan of Air Anchor only giving a small amount of battery gauge. Sometimes, if there is a lot of enemies to AoE down, you wouldn't be using your 700 potency AoE attack, which also means you wouldn't be generating battery gauge either ... Perhaps changing Air Anchor to be a 700 potency attack with a splash damage at 50% on all the other surrounding enemies in addition to gaining battery would make it feel a lot better. Air Anchor looks like an AoE skill too rather than a single target skill in my opinion.

Flamethrower - change into a skill that does more damage under Bioblaster, kinda like a combo effect where a bioblaster DoT will cause Flamethrower to apply an extra DoT. As it is currently, Flamethrower doesn't get used for its full duration since it's slightly weaker than using our AoE (which also gets 5 points into our gauge), which is a shame considering how nice the animation looks. However, it also forces the character to remain at a standstill, which goes against what most people assume a ranged DPS would have - full mobility.

Air Anchor - Good idea, a lot of people want to have an AoE version of it when we can simply slap the both on a single button rather than waste a skill slot when MCH desperately needs buttons.

Flamethrower - Wouldn't work. Or at least it would in dungeon but if you want to make it a viable Single Target option.
When it comes to AoE, Flamethrower is already used like this. The DPS from MCH aoes comes like this: Bio Blaster > Auto Cross Bow > Flamethrower > Spread shot.
It's meant to be used when you don't have Bio Blaster ready or ACB available. Creating a synergy between Bio Blaster and Flamethrower would simply swap the priority between FT and ACB.

Current Flamethrower problem it's that it is a dungeon skill when it's supposed to be a core MCH ability. And staying immobile for 10 seconds is not a good idea no matter the content.
No button should be "Press and lift your hands off you keyboard for 10s". Flamethrower is just that.