Impressive! Sounds like you've got the gist of it.
This can be a long-term OR short-term thing - it is whatever you make it. If you're not comfortable tying money up in this that belongs to your October trip, you could do a single churn and then see how that works for you. You can always cash out into Disney gift cards whenever you feel inclined to.
Instead of starting with eBay gift cards from Target, I would personally start with Target gift cards from eBay. Do you already have an eBay account that is enrolled in eBay Bucks? If so, did you receive any of the recent promos (4x, 5x)?
If your eBay account is already completely ready to go/receiving offers, that's definitely where I would start. That way, you're starting off with a higher potential percentage (up to 10%) than if you had purchased eBay GCs from Target (5%).
The other benefit of going that route is that you would go through Target one less time, thereby decreasing your risk of the dreaded Target ban.
Don't forget to add in the cash back site(s) of your choice - the cash back really adds up when you're dealing with this much money over and over.
I didn't follow your last eBay Bucks question. To try to answer what I think you were asking: eBay bucks are accumulated on a quarterly basis, and then you have one month from the date of issue to use them. The last quarter just ended, so April will essentially be the eBay Bucks spend month. That doesn't necessarily mean there won't be an eBay Bucks promo in April - there was one in Jan. after the end of the last quarter.
Outside of the "spend" month after quarter-end, there are typically a few eBay Bucks promos a month. A few days ago,
@DIS_MERI posted a list of the dates + promo amounts for the past 6 months or so.
Feel free to ask questions - it can be a lot at first! You've clearly done your work in trying to get the process down, so you've done 90% of the work.
