Its hard!
F Sats has a strong, unique toolkit for playing neutral. In addition to her solid normals F shares tools like 22X and 5C with Half Moon. This allows Full to play a more defensive playstyle in neutral, focused on space control, whiff punishment, and occasional gorilla rushdown using her burst movement and big buttons.
Keep em out or go in and catch em off guard.
5B can be used as a situational anti air but you primarily want to wall out your opponent's ground approach/pokes with its disjoint or abuse its forward movement for an approach of your own. With Satsuki's strong burst movement 66 > 5B is FAST and covers a deceptive amount of distance when used towards the end of a dash.
Want to cover space without giving up ground? Use 2B! When spaced just outside of 2A~2B ranges it can serve as a very strong poke with excellent proration and decent recovery. The disjoint is great at catching moves with extended green so it should be your go-to move for whiff punishing things like Satsuki 2C.
Speaking of 2C being green, only use this move if you are 100 percent confident that it will hit. If you poke with it and they pressed preemptively you DIE. If you dash 2C and they IAD you DIE. Just out of range? DIED. The move is hugely minus on whiff and is disastrous on block. Even cancelled a blocked 2C drastically limits your blockstring options as you have to cancel into a special to make it safe, ending your pressure.
However, this move is awesome for long range punishes as its huge, fast as hell for no reason, and can be hit confirmed at max range with 2C(1) > 236C. Its insane how many things you can punish with this move if you are patient with your trigger finger. The occasional blitz with Dash > 2C can work but dont make it a habit as this move will definitely get you killed.
You can abuse F landing recovery and use 2C to blow people up for mashing intentionally whiffed j.C's but this is a high level strategy best left up to the professionals.
3C and 3[C] are like 2C, they low profile and slide across the ground which makes them very powerful tools to gap close or punish things like fireballs on reaction. Both are hella unsafe on startup whiff and block and will get you killed if used incorrectly. Only use these if you have a good reason.
5C is a bit slow to chuck out preemptively to cover ground approaches and the clash box is honestly more pain than its worth. More on this move later.
Other than 5B, 5[C] is FSats’ go-to normal for midrange space control as it is HUGE, recovers fast, and gives absolutely ludicrous reward on CH. If you have the space to chuck this move out there really isnt a reason not to. After a step the hitbox covers everything in front of you and if they get hit they lose 6000+ health. Use this.
22A and 22B are a powerful low investment way to check an opponent in neutral, punish projectile/summon use from range and persuade people to jump. 22A is low commitment with low reward but has slower startup. 22B is fast and safe if spaced well but has the added boon of being EX Cancellable. Abuse this by buffering 623C every single time you check an opponent with this move. If they jump, they die.
IABD j.B is a strong way to retreat safely while covering the space in front of you. Think of it like a very small FTohno IABD j.C. Very strong into rushdown characters. j.C can also be used here but can be impossible to confirm if you catch the opponent rising with a j9 or something. Rattling out IABD j.B's to adjust your positioning can dissuade the opponent from advancing on the ground while disguising an IAD approach of your own.
Use 236C to abuse characters with a punishable neutral/presure tool (Aoko orb set/fireball, Wara pillars/summons, Mech AAD). This is probably why you picked F Moon. Matchup defining.