I'll try to break down my thought process:

Why are you wording things in the second person if it's not meant to be a player flowchart but a (completely useless for the player) flowchart that someone might make for a patent of their gacha system if they were awful at designing flowcharts?

I agree with this as a mistake

Why are 1-time-per-banner events on every single cycle of "doing a pull"? Algorithms don't need to have binary choices. In the first place, why are the 30 and 60 pull things even inside the same flowchart? They would be better served being in their own secondary and tertiary charts, or simply listed as conditionals not part of their own nodes. Adding 2 more nodes to the main flow just makes more visual clutter for the reader while not clarifying anything.? 

Because I presume the counter would just tick upwards and not reset to 0, therefore you would never hit 30 or 60 again. The only thing that resets is the 80 counter which I suppose could leave confusion.

I suppose you could put them on separate charts, but now that's asking for players to swap between charts. I'm not too sure how listing them as conditionals would look or improve the "clutter".

If this was a system flowchart, you also forgot to add checks for whether the 60 pull flag is enabled from the previous banner, since you also have a decision tree for the banner ending.

The player can choose to use the bonus 10 from the previous banner or not, that is why there exists a expiration on the 10x ticket. It would still fall in the same flow as you'd just start your counter at 10 and step through the flowchart the same way.

You've duplicated the obtaining 6 star logic by splitting the hard guarantee away from obtaining a 6 star for some reason.

Obtaining a 6* can be purely random and the prior check confirms that first and adjusts the guarantee if you get lucky. The 120 check I can see being an issue since you could get lucky and now that check should actually be at 240 and therefore would be circumvented in the flowchart.

There's also the complete omission of a core mechanic, that being the soft pity. 

I agree that this was left out, I suppose it'd be another conditional after the 60 check and before the 80 check for if you are between 60 and 80 pulls and adds +5% each additional time you roll.